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                                                                   EXHIBIT 10.26



                                                                         Estroff






                                December 1, 2000



Mr. Richard A. Parlontieri
Emissions Testing, Inc.
400 Colony Park
Building 104, Suite 600
Cumming, Georgia  30041

          Re:  Letter Agreement Regarding 110,000 Shares of the Common Stock of
               Emissions Testing, Inc., a Georgia Corporation (the "Company"),
               Owned of Record by William S. Estroff ("Estroff")

Dear Mr. Parlontieri:

     As you know, Estroff is the owner of record of 110,000 shares of the common
stock, no par value per share, of the Company.

     The Company has filed a registration statement on Form S-1 (the
"Registration Statement") with the Securities and Exchange Commission (the
"SEC") for the registration of certain shares of the Company's common stock
("Common Stock"), in a public offering (the "Offering") under the Securities Act
of 1933, as amended (the "Act"). Among the shares of Common Stock to be
registered in the Offering are 55,000 shares of Common Stock owned of record by
Estroff ( the "Registered Shares"). The balance of the shares of Common Stock
owned by Estroff, I.E., 55,000 shares, will not be registered with the SEC by
the Company in the Offering (the "Restricted Shares").

     Inasmuch as Estroff wishes to induce the Company to continue its efforts in
connection with the Offering, Estroff hereby agrees with, and represents to, the
Company that Estroff will not, directly or indirectly, sell, offer to sell,
grant an option for the sale of, assign, transfer, pledge, hypothecate or
otherwise encumber or dispose of in any manner, any of the Registered Shares (or
any interest therein) or any of the Restricted Shares (or any interest therein),
INCLUDING, WITHOUT LIMITATION, PURSUANT TO RULE 144 OR RULE 144A UNDER THE ACT,
from and after the date hereof except as follows: The Company agrees that
Estroff shall have the right to sell, offer to sell, grant an option for the
sale of, assign, transfer, pledge, hypothecate or otherwise encumber and/or
dispose of in any manner, all or any part of the Registered Shares and all or
any part of the Restricted Shares at any time after the earlier of (I) 12:01 AM
(Atlanta, Georgia time) on October 1, 2001, or (II) the date and time that the
Company has reduced to $250,000 or below

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Emissions Testing, Inc.
December 1, 2000
Page 2


the outstanding aggregate principal amount of the Company's indebtedness to GCA
Strategic Investment Fund Limited, a Bermuda corporation ("GCA") (or its
assignees) under the convertible debentures issued and sold (before or after the
date hereof) by the Company pursuant to the terms of that certain Securities
Purchase Agreement dated effective as of June 1, 2000 between the Company and
GCA, as the same may be amended from time to time.

     Estroff agrees and understands that:

          (a)  Any sale or other transaction involving all or any part of
               Registered Shares and all or any part of the Restricted Shares
               are, and shall hereafter remain, subject to all applicable
               federal and state securities laws and regulations.

          (b)  The Company may place a legend reflecting this letter and terms
               hereofon any certificate evidencing all or any part of the shares
               described herein, and may give written notice of this letter, and
               the terms hereof, to the Company's transfer agent;

          (c)  This letter, and the terms hereof, shall be binding upon Estroff
               and the successors and assigns of Estroff; and

          (d)  The Company is relying upon the agreements and representations of
               Estroff set forth in this letter in filing the Registration
               Statement and amendments thereto and in consummating the
               Offering.

     The Company agrees that, upon the occurrence of the event described in
clause (II) above, the Company shall give prompt written notice thereof to
Estroff at the last known address then available to the Company.

     The parties hereto agree that this Letter Agreement shall not be amended,
modified or terminated without the prior written consent of GCA, which consent
may be granted or denied in the sole discretion of GCA.

     If the foregoing meets with your understanding of our agreement, please so
signify by signing and returning this Letter Agreement to us.

<TABLE>
<S>                                  <C>
                                     Very truly yours,



                                     /s/ William S. Estroff
                                     ------------------------------------
                                     William S. Estroff
</TABLE>


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Emissions Testing, Inc.
December 1, 2000
Page 3


Agreed to and accepted as of the
day and year first above written.


EMISSIONS TESTING, INC.



By: /s/ Rich Parlontieri
    ------------------------------
   Name: Rich Parlontieri
         -------------------------
   Position: President/CEO
            ----------------------