Re: INGEN TECHNOLOGIES, INC., (the "Company") - AMENDMENT OF NOTES

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EXHIBIT 10.50


                            INGEN TECHNOLOGIES, INC.
                            35193 AVENUE "A", SUITE-C
                                YUCAIPA, CA 92399

August 29, 2008

AJW Partners, LLC
New Millennium Capital Partners II, LLC
AJW Master Fund, Ltd.
AJW Offshore, Ltd.
AJW Qualified Partners, LLC
1044 Northern Boulevard
Suite 302
Roslyn, New York 11576

Re:       INGEN TECHNOLOGIES, INC., (the "Company") -
         AMENDMENT OF NOTES

Ladies and Gentlemen:

      This letter sets for the agreement of the parties hereto to amend the
Applicable Percentage and the Interest Rate (as defined in the Notes) of all the
Notes, which are convertible into shares of the Company's common stock, no par
value per share (the "COMMON STOCK"), ever issued by the Company to the
investors listed in the signature pages hereto (collectively, the
"INVESTORS")(the "Notes").

      By execution hereof, for good and valuable consideration the receipt and
sufficiency of which is hereby acknowledged, the parties hereto agree that:

      1.     The applicable Percentage (as defined in each of the Notes) shall be
            40%.

      2.     The Interest Rate (as defined in each of the Notes), effective