For the purposes of this Agreement, notices and all other communications provided for in this Agreement shall be in writing and shall be duly given when delivered or when mailed by United States registered or certified mail, return receipt requested, postage prepaid, addressed to the President of the Company, at One Technology Way, Norwood, Massachusetts 02062, and to you at the address shown above or to such other address as either the Company or you may have furnished to the other in writing in accordance herewith, except that notice of change of address shall be effective only upon receipt.