Common use of FORM OF ELECTION TO EXERCISE Clause in Contracts

FORM OF ELECTION TO EXERCISE. (To Be Executed Upon Exercise of Contingent Warrant) The undersigned hereby irrevocably elects to exercise ____ of the Contingent Warrants represented by this Warrant Certificate and purchase the number of Warrant Shares issuable upon the exercise of such Contingent Warrants and herewith tenders payment for such Warrant Shares as follows: (Check One) [ ] $__________ in cash or by certified or official bank check; or [ ] by surrender of Contingent Warrants pursuant to a Cashless Exercise (as defined in the Warrant Agreement) at the current Cashless Exercise Ratio. The undersigned requests that a certificate representing such Warrant Shares be registered in the name of __________________________________________________________ whose address is _______________________________________________________________ and that such Warrant Shares be delivered to ___________________________________ whose address is ______________________________________________________________. Any cash payments to be paid in lieu of a fractional Warrant Share should be made to ________________________________________________________________________ whose address is _______________________________________________________________ and the check representing payment thereof should be delivered to ______________ whose address is ______________________________________________________________. Dated _____________________, ____ Name of holder of Warrant Certificate: ___________________________ (Please Print) Tax Identification or Social Security Number: ________________________________________________________ Address: _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ Signature: _____________________________________________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration or enlargement or any change whatever and if the certificate representing the Warrant Shares or any Warrant Certificate representing Contingent Warrants not exercised is to be registered in a name other than that in which this Warrant Certificate is registered or if any cash payment to be paid in lieu of a fractional Warrant Share is to be made to a person other than the registered holder of this Warrant Certificate, the signature of the holder hereof must be guaranteed as provided in the Warrant Agreement. Signature Guaranteed: ______________________________ [FORM OF ASSIGNMENT] For value received _______________________________________ hereby sells, assigns and transfers unto _______________________________________ the within Warrant Certificate, together with all right, title and interest therein, and does hereby irrevocably constitute and appoint _______________________________________ attorney, to transfer said Warrant Certificate on the books of the within-named Company, with full power of substitution in the premises. Dated ________________, _____ Signature: ___________________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration or enlargement or any change whatever. Signature Guaranteed: _________________________________ EXHIBIT B Form of Certificate for Transfers of Certificated Warrants Continental Stock Transfer & Trust Company ▇ ▇▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ Attention: Compliance Department Re: Contingent Warrants of NEXTLINK Communications, Inc. (the "Warrants") Reference is made to the Warrant Agreement, dated as of January 31, 1997 (the "Warrant Agreement"), between NEXTLINK Communications, Inc. (the "Company") and Continental Stock Transfer & Trust Company, as Warrant Agent. Terms used herein and defined in the Warrant Agreement or in Regulation S, Rule 144A or Rule 144 under the Securities Act of 1933 (the "Securities Act") are used herein as so defined. This certificate relates to _______ Contingent Warrants, which are evidenced by the following certificate(s) (the "Specified Warrants"): CUSIP No. _______________________________ CERTIFICATE No(s). _____________________ The person in whose name this certificate is executed below (the "Undersigned") hereby certifies that either (i) it is the sole beneficial owner of the Specified Warrants or (ii) it is acting on behalf of all the beneficial owners of the Specified Warrants and is duly authorized by them to do so. Such beneficial owner or owners are referred to herein collectively as the "Owner". The Specified Warrants are registered in the name of the Undersigned, as or on behalf of the Owner. The Owner has requested that the Specified Warrants be transferred to a person (the "Transferee") who will take delivery in the form of an interest in the Global Warrant. In connection with such transfer, the Owner hereby certifies that such transfer is being effected in accordance with (a) either: (Check one) |_| Rule 144A, |_| Rule 904, or |_| Rule 144 under the Securities Act and (b) all applicable securities laws of the states of the United States and other jurisdictions. Accordingly, the Owner hereby further certifies as follows with respect to the type of transfer indicated herein:

FORM OF ELECTION TO EXERCISE. (To Be Executed Upon Exercise of Contingent Warrantbe exercised by the registered holder if such holder desires to exercise the Rights Certificate.) TO: STELLAR BIOTECHNOLOGIES INC. and COMPUTERSHARE INVESTOR SERVICES INC. The undersigned hereby irrevocably Irrevocably elects to exercise ____ of the Contingent Warrants represented by this Warrant Certificate and purchase the number of Warrant Shares issuable upon the exercise of such Contingent Warrants and herewith tenders payment for such Warrant Shares as follows: (Check One) [ ] $__________ in cash or by certified or official bank check; or [ ] by surrender of Contingent Warrants pursuant to a Cashless Exercise (as defined in the Warrant Agreement) at the current Cashless Exercise Ratio. The undersigned requests that a certificate representing such Warrant Shares be registered in the name of __________________________________________________________ whose address is whole Rights represented by the attached Rights Certificate to purchase the Common Shares or other securities, if applicable, issuable upon the exercise of such Rights and requests that certificates for such securities be issued in the name of: _______________________________________________________________ and that such Warrant Shares be delivered to ___________________________________ whose address is ______________________________________________________________. Any cash payments to be paid in lieu of a fractional Warrant Share should be made to ________________________________________________________________________ whose address is (Name) _____________________________________________________________________________________ and the check representing payment thereof should be delivered to ______________ whose address is (Address) ______________________________________________________________. Dated _____________________, ____ Name of holder of Warrant Certificate: (City and Province) ­­­­­­­­­­­___________________________ (Please Print) Tax Identification or Social Security Number: ___________________________________________________________ AddressSocial Insurance Number or other taxpayer identification number If such number of Rights shall not be all the Rights evidenced by this Rights Certificate, a new Rights Certificate for the balance of such Rights shall be registered in the name of and delivered to: _____________________________________________________________________________________ (Name) _____________________________________________________________________________________ (Address) _____________________________________________________________________________________ Signature: (City and Province) _____________________________________________________________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration Social Insurance Number or enlargement or any change whatever and if the certificate representing the Warrant Shares or any Warrant Certificate representing Contingent Warrants not exercised is to be registered in a name other than that in which this Warrant Certificate is registered or if any cash payment to be paid in lieu of a fractional Warrant Share is to be made to a person other than the registered holder of this Warrant Certificate, the signature of the holder hereof must be guaranteed as provided in the Warrant Agreement. Signature Guaranteedtaxpayer identification number Dated: ______________________________ [FORM OF ASSIGNMENT] For value received _______________________________________ Signature Signature Guaranteed: (Signature must correspond to name as written upon the face of this Rights Certificate in every particular, without alteration or enlargement or any change whatsoever.) *The signature of the person executing this form of transfer must be guaranteed by a chartered bank or an eligible guarantor institution with membership in an approved signature guarantee medallion program. The undersigned party exercising Rights hereunder, hereby sellsrepresents, assigns for the benefit of all holders of Rights and transfers unto Common Shares, that the Rights evidenced by this Rights Certificate are not, and, to the knowledge of the undersigned, have never been, Beneficially owned by an Acquiring Person or an Affiliate or Associate thereof or a Person acting jointly or in concert with an Acquiring Person or an Affiliate or Associate thereof. Capitalized terms shall have the meaning ascribed thereto in the Shareholder Rights Plan Agreement. Dated: ___________________________ ___________________________________ the within Warrant Certificate, together with all right, title and interest therein, and does hereby irrevocably constitute and appoint _______________________________________ attorney, to transfer said Warrant Certificate on the books of the within-named Company, with full power of substitution in the premises. Dated ________________, _____ Signature: ___________________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration or enlargement or any change whatever. Signature Guaranteed: _________________________________ EXHIBIT B Form of Certificate for Transfers of Certificated Warrants Continental Stock Transfer & Trust Company ▇ ▇▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ Attention: Compliance Department Re: Contingent Warrants of NEXTLINK Communications, Inc. (the "Warrants") Reference is made to the Warrant Agreement, dated as of January 31, 1997 (the "Warrant Agreement"), between NEXTLINK Communications, Inc. (the "Company") and Continental Stock Transfer & Trust Company, as Warrant Agent. Terms used herein and defined in the Warrant Agreement or in Regulation S, Rule 144A or Rule 144 under the Securities Act of 1933 (the "Securities Act") are used herein as so defined. This certificate relates to _______ Contingent Warrants, which are evidenced by the following certificate(s) (the "Specified Warrants"): CUSIP No. _______________________________ CERTIFICATE No(s). _____________________ The person in whose name this certificate is executed below (the "Undersigned") hereby certifies that either (i) it is the sole beneficial owner of the Specified Warrants or (ii) it is acting on behalf of all the beneficial owners of the Specified Warrants and is duly authorized by them to do so. Such beneficial owner or owners are referred to herein collectively as the "Owner". The Specified Warrants are registered in the name of the Undersigned, as or on behalf of the Owner. The Owner has requested that the Specified Warrants be transferred to a person (the "Transferee") who will take delivery in the form of an interest in the Global Warrant. In connection with such transfer, the Owner hereby certifies that such transfer is being effected in accordance with (a) either: (Check one) |_| Rule 144A, |_| Rule 904, or |_| Rule 144 under the Securities Act and (b) all applicable securities laws of the states of the United States and other jurisdictions. Accordingly, the Owner hereby further certifies as follows with respect to the type of transfer indicated herein:

FORM OF ELECTION TO EXERCISE. (To Be Executed Upon Exercise of Contingent Warrant) TO: CAE INC. The undersigned hereby irrevocably elects to exercise ________ of the Contingent Warrants whole Rights represented by this Warrant the attached Rights Certificate and to purchase the number of Warrant Common Shares issuable upon the exercise of such Contingent Warrants Rights and herewith tenders payment requests that certificates for such Warrant Shares as followsbe issued to: (Check One) [ ] $____________________________ in cash or (NAME) ____________________________ (ADDRESS) ____________________________ (CITY AND STATE OR PROVINCE) If such number of Rights shall not be all the Rights evidenced by certified or official bank check; or [ ] by surrender this Rights Certificate, a new Rights Certificate for the balance of Contingent Warrants pursuant to a Cashless Exercise (as defined in the Warrant Agreement) at the current Cashless Exercise Ratio. The undersigned requests that a certificate representing such Warrant Shares Rights shall be registered in the name of and delivered to: ____________________________ (NAME) ____________________________ (ADDRESS) ____________________________ (CITY AND STATE OR PROVINCE) __________________________________________________________ whose address is SOCIAL INSURANCE, SOCIAL SECURITY OR OTHER TAXPAYER NUMBER Dated ___________________ Signature Guaranteed ________________________________________________ Signature (Signature must correspond to name as written upon the face of this Rights Certificate in every particular, without alteration or enlargement or any change whatsoever) Signature must be guaranteed by a Canadian chartered bank, a Canadian trust company or a member of a recognized stock exchange or a member of the Securities Transfer Association Medallion Program (Stamp). TO BE COMPLETED IF TRUE The undersigned hereby represents, for the benefit of all holders of Rights and Common Shares, that the Rights evidenced by this Rights Certificate are not, and, to the knowledge of the undersigned, have never been, Beneficially Owned by an Acquiring Person or an Affiliate or Associate thereof or any Person acting jointly or in consent with any of the foregoing or any Affiliate or Associate of such Warrant Shares be delivered to _Person (as defined in the Rights Agreement). __________________________________ whose address is ______________________________________________________________. Any cash payments to be paid in lieu of a fractional Warrant Share should be Signature ASSIGNMENT OF AGENCIES AGREEMENT THIS AGREEMENT made to ________________________________________________________________________ whose address is _______________________________________________________________ and the check representing payment thereof should be delivered to ______________ whose address is ______________________________________________________________. Dated _____________________, ____ Name of holder of Warrant Certificate: ___________________________ (Please Print) Tax Identification or Social Security Number: ________________________________________________________ Address: _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ Signature: _____________________________________________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration or enlargement or any change whatever and if the certificate representing the Warrant Shares or any Warrant Certificate representing Contingent Warrants not exercised is to be registered in a name other than that in which this Warrant Certificate is registered or if any cash payment to be paid in lieu of a fractional Warrant Share is to be made to a person other than the registered holder of this Warrant Certificate, the signature of the holder hereof must be guaranteed as provided in 15th day of January, 2001 BETWEEN: CAE INC., a company incorporated under the Warrant Agreement. Signature Guaranteed: ______________________________ [FORM OF ASSIGNMENT] For value received _______________________________________ hereby sells, assigns and transfers unto _______________________________________ the within Warrant Certificate, together with all right, title and interest therein, and does hereby irrevocably constitute and appoint _______________________________________ attorney, to transfer said Warrant Certificate on the books laws of the within-named Company, with full power of substitution in the premises. Dated ________________, _____ Signature: ___________________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration or enlargement or any change whatever. Signature Guaranteed: _________________________________ EXHIBIT B Form of Certificate for Transfers of Certificated Warrants Continental Stock Transfer & Trust Company ▇ ▇▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ Attention: Compliance Department Re: Contingent Warrants of NEXTLINK Communications, Inc. C.B.C.A (the "Warrants") Reference is made to the Warrant Agreement, dated as of January 31, 1997 (the "Warrant Agreement"), between NEXTLINK Communications, Inc. (hereinafter called the "Company") and Continental Stock Transfer & Trust CompanyPARTY OF THE FIRST PART AND: MONTREAL TRUST COMPANY, as Warrant Agent. Terms used herein and defined in the Warrant Agreement or in Regulation S, Rule 144A or Rule 144 a trust company existing under the Securities Act laws of 1933 Canada PARTY OF THE SECOND PART AND: MONTREAL TRUST COMPANY OF CANADA, a trust company existing under the laws of Canada (the "Securities Act") are used herein as so defined. This certificate relates to _______ Contingent WarrantsMontreal Trust Company and Montreal Trust Company of Canada being hereinafter referred to, which are evidenced by the following certificate(s) (the "Specified Warrants"): CUSIP No. _______________________________ CERTIFICATE No(s). _____________________ The person in whose name this certificate is executed below (the "Undersigned") hereby certifies that either (i) it is the sole beneficial owner of the Specified Warrants individually or (ii) it is acting on behalf of all the beneficial owners of the Specified Warrants and is duly authorized by them to do so. Such beneficial owner or owners are referred to herein collectively as the context may require, as "OwnerMontreal Trust". The Specified Warrants are registered ) PARTY OF THE THIRD PART AND: COMPUTERSHARE TRUST COMPANY OF CANADA, a trust company existing under the laws of Canada with an office in the name City of Toronto, in the Undersigned, as or on behalf Province of the Owner. The Owner has requested that the Specified Warrants be transferred to a person Ontario (the hereinafter called "TransfereeComputershare") who will take delivery in the form of an interest in the Global Warrant. In connection with such transfer, the Owner hereby certifies that such transfer is being effected in accordance with (a) either: (Check one) |_| Rule 144A, |_| Rule 904, or |_| Rule 144 under the Securities Act and (b) all applicable securities laws of the states of the United States and other jurisdictions. Accordingly, the Owner hereby further certifies as follows with respect to the type of transfer indicated herein:PARTY OF THE FOURTH PART

FORM OF ELECTION TO EXERCISE. (To Be Executed Upon Exercise of Contingent Warrantbe executed if holder desires to exercise the Rights Certificate.) TO: UTILICORP UNITED INC. The undersigned hereby irrevocably elects to exercise ____ of the Contingent Warrants represented by this Warrant Certificate and purchase the number of Warrant Shares issuable upon the exercise of such Contingent Warrants and herewith tenders payment for such Warrant Shares as follows: (Check One) [ ] $__________ in cash or by certified or official bank check; or [ ] by surrender of Contingent Warrants pursuant to a Cashless Exercise (as defined in the Warrant Agreement) at the current Cashless Exercise Ratio. The undersigned requests that a certificate representing such Warrant Shares be registered in the name of __________________________________________________________ whose address is _______________________________________________________________ whole Rights represented by the attached Rights Certificate to purchase the shares of Preference Stock issuable upon the exercise of such Rights and requests that certificates for such Warrant Shares shares be delivered to ___________________________________ whose address is ______________________________________________________________. Any cash payments to be paid issued in lieu of a fractional Warrant Share should be made to ________________________________________________________________________ whose address is _______________________________________________________________ and the check representing payment thereof should be delivered to ______________ whose address is ______________________________________________________________. Dated _____________________, ____ Name of holder of Warrant Certificatename of: ___________________________ (Please Print) Tax Identification or ------------------------------------------- Address: ----------------------------------- Social Security or Other Taxpayer Identification Number: ________________________________________________________ --------------------- If such number of Rights shall not be all the Rights evidenced by this Rights Certificate, a new Rights Certificate for the balance of such Rights shall be registered in the name of and delivered to: ------------------------------------------- Address: _____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ Signature----------------------------------- Social Security or Other Taxpayer Identification Number: _____________________________________________________________________ Note--------------------- Dated: The above signature ------------------ Signature Guaranteed: --------------------------------- Signature (Signature must correspond with the to name as written upon the face of this Warrant Rights Certificate in every particular, without alteration or enlargement or any change whatever and if the certificate representing the Warrant Shares or any Warrant Certificate representing Contingent Warrants not exercised is to be registered in a name other than that in which this Warrant Certificate is registered or if any cash payment to be paid in lieu of a fractional Warrant Share is to be made to a person other than the registered holder of this Warrant Certificate, the signature of the holder hereof whatsoever) Signatures must be guaranteed by an eligible guarantor institution (banks, stockbrokers, savings and loan associations and credit unions with membership in an approved signature guarantee Medallion program), pursuant to SEC Rule 17Ad-15. -------------------------------------------------------------------------------- (To be completed if true) The undersigned hereby represents, for the benefit of all holders of Rights and shares of Common Stock, that the Rights evidenced by the attached Rights Certificate are not, and, to the knowledge of the undersigned, have never been, Beneficially Owned by an Acquiring Person or an Affiliate or Associate thereof (as provided defined in the Warrant Rights Agreement). --------------------------------- Signature Guaranteed: ______________________________ [-------------------------------------------------------------------------------- NOTICE In the event the certification set forth above is not completed in connection with a purported exercise, the Company will deem the Beneficial owner of the Rights. evidenced by the attached Rights Certificate to be an Acquiring Person or an Affiliate or Associate thereof (as defined in the Rights Agreement) or a transferee of any of the foregoing and accordingly will deem the Rights evidenced by such Rights Certificate to be void and not transferable or exercisable. EXHIBIT B FORM OF ASSIGNMENT] For value received _______________________________________ hereby sells, assigns and transfers unto _______________________________________ the within Warrant Certificate, together with all right, title and interest therein, and does hereby irrevocably constitute and appoint _______________________________________ attorney, CERTIFICATE OF DESIGNATION OF UTILICORP UNITED INC. SERIES A PARTICIPATING CUMULATIVE PREFERENCE STOCK Pursuant to transfer said Warrant Certificate on the books Sections 151 of the within-named CompanyGeneral Corporation Law of the State of Delaware UtiliCorp United Inc., with full power a corporation organized and existing under and by virtue of substitution in The General Corporation Law of Delaware, DOES HEREBY CERTIFY: That at a meeting of the premises. Dated ________________, _____ Signature: ___________________________________________ Note: The above signature must correspond with the name as written upon the face Board of this Warrant Certificate in every particular, without alteration or enlargement or any change whatever. Signature Guaranteed: _________________________________ EXHIBIT B Form Directors of Certificate for Transfers of Certificated Warrants Continental Stock Transfer & Trust Company ▇ ▇▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ Attention: Compliance Department Re: Contingent Warrants of NEXTLINK Communications, UtiliCorp United Inc. (the "WarrantsCorporation") Reference is made the following resolution was duly adopted creating 60,000 shares of Preference Stock, designated as Series A Participating Cumulative Preference Stock. RESOLVED, that pursuant to the Warrant Agreement, dated as of January 31, 1997 (the "Warrant Agreement"), between NEXTLINK Communications, Inc. (the "Company") authority granted to and Continental Stock Transfer & Trust Company, as Warrant Agent. Terms used herein and defined vested in the Warrant Agreement or Board of Directors of this Corporation in Regulation Saccordance with the provisions of the Certificate of Incorporation, Rule 144A or Rule 144 under a series of Preference Stock of the Securities Act Corporation be, and it hereby is created, and the designation and amount thereof and the relative rights, preferences and limitations thereof (in addition to the provisions set forth in the Certificate of 1933 (Incorporation, of the "Securities Act") are used herein as so defined. This certificate relates to _______ Contingent WarrantsCorporation, which are evidenced by applicable to the following certificate(s) (the "Specified Warrants"): CUSIP No. _______________________________ CERTIFICATE No(s). _____________________ The person in whose name this certificate is executed below (the "Undersigned") hereby certifies that either (i) it is the sole beneficial owner of the Specified Warrants or (ii) it is acting on behalf Preference Stock of all the beneficial owners of the Specified Warrants classes and is duly authorized by them to do so. Such beneficial owner or owners series) are referred to herein collectively as the "Owner". The Specified Warrants are registered in the name of the Undersigned, as or on behalf of the Owner. The Owner has requested that the Specified Warrants be transferred to a person (the "Transferee") who will take delivery in the form of an interest in the Global Warrant. In connection with such transfer, the Owner hereby certifies that such transfer is being effected in accordance with (a) either: (Check one) |_| Rule 144A, |_| Rule 904, or |_| Rule 144 under the Securities Act and (b) all applicable securities laws of the states of the United States and other jurisdictions. Accordingly, the Owner hereby further certifies as follows with respect to the type of transfer indicated hereinfollows:

FORM OF ELECTION TO EXERCISE. (To Be Executed Upon Exercise of Contingent Warrantbe exercised by the registered holder if such holder desires to exercise the Rights Certificate.) TO: Canplats Resources Corporation and Computershare Investor Services Inc. The undersigned hereby irrevocably elects to exercise ____ of the Contingent Warrants represented by this Warrant Certificate and purchase the number of Warrant Shares issuable upon the exercise of such Contingent Warrants and herewith tenders payment for such Warrant Shares as follows: (Check One) [ ] $__________ in cash or by certified or official bank check; or [ ] by surrender of Contingent Warrants pursuant to a Cashless Exercise (as defined in the Warrant Agreement) at the current Cashless Exercise Ratio. The undersigned requests that a certificate representing such Warrant Shares be registered in the name of __________________________________________________________ whose address is whole Rights represented by the attached Rights Certificate to purchase the Common Shares or other securities, if applicable, issuable upon the exercise of such Rights and requests that certificates for such securities be issued in the name of: _______________________________________________________________ and that such Warrant Shares be delivered to ___________________________________ whose address is ______________________________________________________________. Any cash payments to be paid in lieu of a fractional Warrant Share should be made to ________________________________________________________________________ whose address is (Name) ______________________________________________________________________________ and the check representing payment thereof should be delivered to ______________ whose address is (Address) ______________________________________________________________. Dated _____________________, ____ Name of holder of Warrant Certificate: (City and Province) ___________________________ (Please Print) Tax Identification or Social Security Number: ________________________________________________________ AddressSocial Insurance, Social Security or other taxpayer identification number. If such number of Rights shall not be all the Rights evidenced by this Rights Certificate, a new Rights Certificate for the balance of such Rights shall be registered in the name of and delivered to: ______________________________________________________________________________ (Name) ______________________________________________________________________________ (Address) ______________________________________________________________________________ Signature: (City and Province) ______________________________________________________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particularSocial Insurance, without alteration Social Security or enlargement or any change whatever and if the certificate representing the Warrant Shares or any Warrant Certificate representing Contingent Warrants not exercised is to be registered in a name other than that in which this Warrant Certificate is registered or if any cash payment to be paid in lieu of a fractional Warrant Share is to be made to a person other than the registered holder of this Warrant Certificate, the signature of the holder hereof must be guaranteed as provided in the Warrant Agreementtaxpayer identification number. Signature GuaranteedDated: ______________________________ [FORM OF ASSIGNMENT] For value received _______________________________________ hereby sells, assigns and transfers unto _______________________________________ the within Warrant Certificate, together with all right, title and interest therein, and does hereby irrevocably constitute and appoint _______________________________________ attorney, to transfer said Warrant Certificate on the books of the within-named Company, with full power of substitution in the premises. Dated ________________, _____ Signature: ___________________________________________ NoteSignature Guaranteed: The above signature (Signature must correspond with the to name as written upon the face of this Warrant Rights Certificate in every particular, without alteration or enlargement or any change whateverwhatsoever.) Signature must be guaranteed by a major Canadian Schedule I chartered bank, a major trust company in Canada or a member of an acceptable Medallion Signature Guarantee Program (STAMP, SEMP, MSP). The Guarantor must affix a stamp bearing the actual words “Signature Guaranteed: ”. In the USA, signature guarantees must be done by members of a “Medallion Signature Guarantee Program” only. Please note, signature guarantees are not accepted from Treasury Branches, Credit Unions or Caisse Populaires unless they are members of the STAMP Program. CERTIFICATE (To be completed if true.) The undersigned party exercising and/or transferring Rights hereunder, hereby represents, for the benefit of all holders of Rights and Common Shares, that the Rights evidenced by this Rights Certificate are not, and, to the knowledge of the undersigned, have never been, Beneficially owned by an Acquiring Person or an Affiliate or Associate thereof or a Person acting jointly or in concert with an Acquiring Person or an Affiliate or Associate thereof. Capitalized terms shall have the meaning ascribed thereto in the Shareholder Rights Plan Agreement. __________________________________ EXHIBIT B Form of Certificate for Transfers of Certificated Warrants Continental Stock Transfer & Trust Company ▇ ▇▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ Attention: Compliance Department Re: Contingent Warrants of NEXTLINK Communications, Inc. Signature (the "Warrants") Reference is made To be attached to the Warrant Agreement, dated as of January 31, 1997 (the "Warrant Agreement"each Rights Certificate.), between NEXTLINK Communications, Inc. (the "Company") and Continental Stock Transfer & Trust Company, as Warrant Agent. Terms used herein and defined in the Warrant Agreement or in Regulation S, Rule 144A or Rule 144 under the Securities Act of 1933 (the "Securities Act") are used herein as so defined. This certificate relates to _______ Contingent Warrants, which are evidenced by the following certificate(s) (the "Specified Warrants"): CUSIP No. _______________________________ CERTIFICATE No(s). _____________________ The person in whose name this certificate is executed below (the "Undersigned") hereby certifies that either (i) it is the sole beneficial owner of the Specified Warrants or (ii) it is acting on behalf of all the beneficial owners of the Specified Warrants and is duly authorized by them to do so. Such beneficial owner or owners are referred to herein collectively as the "Owner". The Specified Warrants are registered in the name of the Undersigned, as or on behalf of the Owner. The Owner has requested that the Specified Warrants be transferred to a person (the "Transferee") who will take delivery in the form of an interest in the Global Warrant. In connection with such transfer, the Owner hereby certifies that such transfer is being effected in accordance with (a) either: (Check one) |_| Rule 144A, |_| Rule 904, or |_| Rule 144 under the Securities Act and (b) all applicable securities laws of the states of the United States and other jurisdictions. Accordingly, the Owner hereby further certifies as follows with respect to the type of transfer indicated herein:

FORM OF ELECTION TO EXERCISE. (To Be Executed Upon be executed upon exercise of Warrants on the Exercise of Contingent WarrantDate) The undersigned hereby irrevocably elects to exercise ____ [ ]of the Contingent Warrants represented by this Warrant Certificate and purchase for the whole number of Warrant Shares issuable upon the exercise of such Contingent Warrants and herewith tenders payment for such Warrant Shares as follows: (Check One) [ ] $__________ in cash or by certified or official bank check; or [ ] by surrender of Contingent Warrants pursuant to a Cashless Exercise (as defined in the Warrant Agreement) at the current Cashless Exercise RatioWarrants. The undersigned requests that a certificate representing such Warrant Shares be registered in the name of __________________________________________________________ whose address is _______________________________________________________________ and that such Warrant Shares certificate be delivered to ___________________________________ whose address is ______________________________________________________________. Any cash payments to be paid in lieu of a fractional Warrant Share should be made to ________________________ whose address is __________________________ and the check representing payment thereof should be delivered to ________________________ whose address is ____________________. Dated: Name of holder of Warrant Certificate:___________________________________________ and the check representing payment thereof should be delivered to ______________ whose address is ______________________________________________________________. Dated _____________________, ____ Name of holder of Warrant Certificate: ___________________________ (Please Print) Tax Identification or Social Security Number: ______________________________:__________________________ Address: ______:_______________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ Signature: ________:_____________________________________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration or enlargement or any change whatever and if the certificate representing the Warrant Shares or any Warrant Certificate representing Contingent Warrants not exercised is to be registered in a name other than that in which this Warrant Certificate is registered registered, or if any cash payment to be paid in lieu of a fractional Warrant Share share is to be made to a person other than the registered holder of this Warrant Certificate, the signature of the holder hereof must be guaranteed as provided in the Warrant Agreement. Signature GuaranteedDated: Signature:______________________________ [FORM OF ASSIGNMENT] For value received _______________________________________ hereby sells, assigns and transfers unto _______________________________________ the within Warrant Certificate, together with all right, title and interest therein, and does hereby irrevocably constitute and appoint _______________________________________ attorney, to transfer said Warrant Certificate on the books of the within-named Company, with full power of substitution in the premises. Dated ________________, _____ Signature: ___________________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration or enlargement or any change whatever. Signature Guaranteed: :__________________________________________________ EXHIBIT B Form of Certificate for Transfers of Certificated Warrants Continental Stock Transfer & Trust Company ▇ ▇▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇[FORM OF ASSIGNMENT] For value received __________________________hereby sells, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ Attention: Compliance Department Re: Contingent Warrants of NEXTLINK Communications, Inc. (the "Warrants") Reference is made to the Warrant Agreement, dated as of January 31, 1997 (the "Warrant Agreement"), between NEXTLINK Communications, Inc. (the "Company") assigns and Continental Stock Transfer & Trust Company, as Warrant Agent. Terms used herein and defined in the Warrant Agreement or in Regulation S, Rule 144A or Rule 144 under the Securities Act of 1933 (the "Securities Act") are used herein as so defined. This certificate relates to transfers unto ______________________ Contingent Warrantsthe within Warrant Certificate, which are evidenced by together with all right, title and interest therein, and does hereby irrevocably constitute and appoint __________________ attorney, to transfer said Warrant Certificate on the following certificate(s) (books of the "Specified Warrants"): CUSIP Nowithin-named Company, with full power of substitution in the premises. Dated: Signature:_____________________________________________________________ CERTIFICATE No(s)Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration or enlargement or any change whatever. Signature Guaranteed:__________________________________________________ I SCHEDULE OF EXCHANGES OF CERTIFICATED WARRANTS I The person following exchanges of a part of this Global Warrant for certificated Warrants have been made: Number of Warrants Amount of decrease Amount of Increase this Global Signature of in whose name Number of in Number of Warrant following authorized office Date of Warrants of this certificate Warrants of this such decrease (or of Warrant Exchange Global Warrant Global Warrant increase) Agent This is executed below to be included only if the Warrant is in global form. EXHIBIT B FORM OF LEGEND FOR GLOBAL WARRANT Any Global War-rant authenticated and delivered hereunder shall bear a legend in substantially the following form: THIS SECURITY IS A GLOBAL WARRANT WITHIN THE MEANING OF THE WARRANT AGREEMENT HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITORY OR A NOMINEE OF A DEPOSITORY OR A SUCCESSOR DEPOSITORY. THIS SECURITY IS NOT EXCHANGEABLE FOR SECURITIES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE DEPOSITORY OR ITS NOMINEE EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE WARRANT AGREEMENT, AND NO TRANSFER OF THIS SECURITY (OTHER THAN A TRANSFER OF THIS SECURITY AS A WHOLE BY THE DEPOSITORY TO A NOMINEE OF THE DEPOSITORY OR BY A NOMINEE OF THE DEPOSITORY TO THE DEPOSITORY OR ANOTHER NOMINEE OF THE DEPOSITORY) MAY BE REGISTERED EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE WARRANT AGREEMENT. UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO ISSUER OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE, OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN. EXHIBIT C CERTIFICATE TO BE DELIVERED UPON EXCHANGE OR REGISTRATION OF TRANSFER OF WARRANTS Re: Warrants to Purchase Common Shares (the "UndersignedWarrants") hereby certifies that either (i) it is the sole beneficial owner of the Specified Dayton Superior Corporation This Certificate relates to __________ Warrants or (ii) it is acting on behalf of all the beneficial owners of the Specified Warrants and is duly authorized held by them to do so. Such beneficial owner or owners are referred to herein collectively as the "Owner". The Specified Warrants are registered in the name of the Undersigned, as or on behalf of the Owner. The Owner has requested that the Specified Warrants be transferred to a person (the "TransfereeTransferor") who will take delivery in ). The Transferor has requested the form Warrant Agent by written order to exchange or register the transfer of an interest in the Global Warranta Warrant or Warrants. In connection with such transferrequest and in respect of each such Warrant, the Owner Transferor hereby certifies that the Transferor is familiar with the Warrant Agreement dated as of June 16, 2000, among Dayton Superior Corporation, an Ohio corporation, and United States Trust Company of New York, as warrant agent (the "Warrant Agreement") relating to the above captioned Warrants and the restrictions on transfers thereof as provided in Section 1.08 of such Warrant Agreement, and that the transfer of this Warrant does not require registration under the Securities Act of 1933, as amended (the "Act"), because*: [ ] Such Warrant is being effected acquired for the Transferor's own account, without transfer (in satisfaction of Section 1.08(a)(y)(A) of the Warrant Agreement).' [ ] Such Warrant is being transferred to a qualified institutional buyer (as defined in Rule 144A under the Act) in reliance on Rule 144A or is being transferred in accordance with (a) either: (Check one) |_| Rule 144A, |_| Rule 904, or |_| Regulation S under the Act. [ ] Such Warrant is being transferred in accordance with Rule 144 under the Securities Act Act. [ ] Such Warrant is being transferred in reliance on and (b) all applicable securities laws in compliance with an exemption from the registration requirements of the states Act, other than Rule 144A or Rule 144 or Regulation S under the Act. An opinion of the United States and other jurisdictions. Accordingly, the Owner hereby further certifies as follows with respect counsel to the type effect that such transfer does not require registration under the Act accompanies this Certificate. [INSERT NAME OF TRANSFEROR] By:_____________________________ Date:__________________________ *Check applicable box. EXHIBIT D [Form of transfer indicated hereinTransferee Letter of Representation in Connection with Transfers to Institutional Accredited Investors] DAYTON SUPERIOR CORPORATION ▇▇▇▇ ▇▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇▇▇ ▇▇▇▇▇, ▇▇▇▇▇ ▇▇▇ ▇▇▇▇▇▇, ▇▇▇▇ ▇▇▇▇▇ Attention: General Counsel Ladies and Gentlemen: In connection with our proposed purchase of warrants to purchase Common Shares, no par value (the "Securities"), of Dayton Superior Corporation (the "Company "), we confirm that:

FORM OF ELECTION TO EXERCISE. (To Be Executed Upon Exercise of Contingent Warrant) The undersigned hereby irrevocably elects be executed by the registered holder if such holder desires to exercise ____ of the Contingent Warrants represented by this Warrant Certificate and purchase the number of Warrant Shares issuable upon the exercise of such Contingent Warrants and herewith tenders payment for such Warrant Shares as followsRights Certificate.) TO: (Check One) [ ] $__________ in cash or by certified or official bank check; or [ ] by surrender of Contingent Warrants pursuant to a Cashless Exercise (as defined in the Warrant Agreement) at the current Cashless Exercise Ratio. The undersigned requests that a certificate representing such Warrant Shares be registered in the name of _____________________________________ The undersigned hereby irrevocably elects to exercise ______________________ whose address is whole Rights represented by the attached Rights Certificate to purchase the Common Shares or other securities, if applicable, issuable upon the exercise of such Rights and requests that certificates for such securities be issued in the name of: _______________________________________________________________ and that such Warrant Shares be delivered to ___________________________________ whose address is ______________________________________________________________. Any cash payments to be paid in lieu of a fractional Warrant Share should be made to _________(Name) _______________________________________________________________ whose address is (Address) _______________________________________________________________ (City and the check representing payment thereof should be delivered to ______________ whose address is Province) _______________________________________________________________ Social Insurance Number or other taxpayer identification number. Dated _____________________If such number of Rights shall not be all the Rights evidenced by this Rights Certificate, ____ Name a new Rights Certificate for the balance of holder such Rights shall be registered in the name of Warrant Certificate: ___________________________ (Please Print) Tax Identification or Social Security Number: ________________________________________________________ Addressand delivered to: _____________________________________________________________________ ______(Name) _______________________________________________________________ ______(Address) _______________________________________________________________ Signature: ______(City and Province) _______________________________________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration Social Insurance Number or enlargement or any change whatever and if the certificate representing the Warrant Shares or any Warrant Certificate representing Contingent Warrants not exercised is to be registered in a name other than that in which this Warrant Certificate is registered or if any cash payment to be paid in lieu of a fractional Warrant Share is to be made to a person other than the registered holder of this Warrant Certificate, the signature of the holder hereof must be guaranteed as provided in the Warrant Agreementtaxpayer identification number. Signature GuaranteedDated: ______________________________ [FORM OF ASSIGNMENT] For value received _______________________________________ hereby sells, assigns and transfers unto __Signature _____________________________________ (Please print name of Signatory) Signature Guaranteed: (Signature must correspond to name as written upon the within Warrant Certificateface of this Rights Certificate in every particular, together without alteration or enlargement or any change whatsoever.) Signature must be guaranteed by a Canadian chartered bank or trust company, a member of a recognized stock exchange in Canada, a member of a registered national securities exchange in the United States, a member of the Investment Dealers Association of Canada or National Association of Securities Dealers, Inc. or a commercial bank or trust company having an office or correspondent in Canada or the United States or a member of the Securities Transfer Association Medallion (Stamp) Program CERTIFICATE (To be completed if true.) The undersigned party exercising Rights hereunder, hereby represents, for the benefit of all holders of Rights and Common Shares, that the Rights evidenced by this Rights Certificate are not, and, to the knowledge of the undersigned, have never been, Beneficially Owned by an Acquiring Person or an Affiliate or Associate thereof or a Person acting jointly or in concert with all right, title and interest therein, and does hereby irrevocably constitute and appoint __any of the foregoing. Capitalized terms shall have the meaning ascribed thereto in the Shareholder Rights Agreement. _____________________________________ attorney, to transfer said Warrant Certificate on the books of the within-named Company, with full power of substitution in the premises. Dated ________________, _____ Signature: ______Signature _____________________________________ Note: The above signature must correspond with the name as written upon the face of this Warrant Certificate in every particular, without alteration or enlargement or any change whatever. Signature Guaranteed: _________________________________ EXHIBIT B Form of Certificate for Transfers of Certificated Warrants Continental Stock Transfer & Trust Company ▇ ▇▇▇▇▇▇▇▇ ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇ Attention: Compliance Department Re: Contingent Warrants of NEXTLINK Communications, Inc. (the "Warrants") Reference is made to the Warrant Agreement, dated as of January 31, 1997 (the "Warrant Agreement"), between NEXTLINK Communications, Inc. (the "Company") and Continental Stock Transfer & Trust Company, as Warrant Agent. Terms used herein and defined in the Warrant Agreement or in Regulation S, Rule 144A or Rule 144 under the Securities Act of 1933 (the "Securities Act") are used herein as so defined. This certificate relates to _______ Contingent Warrants, which are evidenced by the following certificate(s) (the "Specified Warrants"): CUSIP No. _______________________________ CERTIFICATE No(s). _____________________ The person in whose name this certificate is executed below (the "Undersigned") hereby certifies that either (i) it is the sole beneficial owner of the Specified Warrants or (ii) it is acting on behalf of all the beneficial owners of the Specified Warrants and is duly authorized by them to do so. Such beneficial owner or owners are referred to herein collectively as the "Owner". The Specified Warrants are registered in the Please print name of the Undersigned, as or on behalf of the Owner. The Owner has requested that the Specified Warrants be transferred to a person (the "Transferee") who will take delivery in the form of an interest in the Global Warrant. In connection with such transfer, the Owner hereby certifies that such transfer is being effected in accordance with (a) either: (Check one) |_| Rule 144A, |_| Rule 904, or |_| Rule 144 under the Securities Act and (b) all applicable securities laws of the states of the United States and other jurisdictions. Accordingly, the Owner hereby further certifies as follows with respect to the type of transfer indicated herein:Signatory)