<PAGE>
 
                                                                     EXHIBIT 4.5

                               CONVERTIBLE NOTE

         $                                                    Irvine, California

     FOR VALUE RECEIVED, on or before May 31, 1997, the undersigned, Grip
Technologies, Inc., a California corporation ("Borrower"), promises to pay to
the order of     , a          , or its successors or assigns ("Holder"), 
at                                                the principal sum of 
  ------------------------------------------------
dollars ($     ) together with simple interest at eight percent (8%) per annum.
The entire outstanding principal and interest amount shall be due and payable
May 31, 1997. Borrower may prepay any or all amounts due under this Note at any
time without penalty; provided, however, that Borrower, as a condition to
prepayment of some or all of balance hereof, shall deliver written notice of its
intention to prepay at least 14 calendar days prior to the date of such
prepayment ("Prepayment Date") and cooperate with Holder in Holder's exercise of
Holder's convertibility rights, as set forth below, if Holder elects to exercise
such rights. Said payments shall first be applied to accrued interest and then
to principal. All payments shall be made in lawful money of the United States.

     This Note is executed pursuant to a Subscription Agreement dated         , 
                                                                      --------
1996, executed by Borrower and Holder.

     The principal and accrued interest on this Note are convertible, at the
option and in the discretion of the Holder, wholly or in part for shares of
Borrower's common stock at a conversion price of $1.75 per share until May 31,
1997 ("Expiration Date"). To exercise Holder's conversion rights, Holder shall
deliver written notice to Borrower no later than 10:00 a.m. Pacific time on the
Expiration Date or the Prepayment Date, whichever is earlier, indicating the
amount of principal and accrued interest to be converted to shares of common
stock. Such shares shall be "restricted securities," as defined in Rule 144
under the Securities Act of 1933, and shall bear a legend indicating their
restricted nature. However, Holder shall have "piggyback" registration rights
with respect to said shares in any registration statement filed by Holder on or
prior to May 31, 1997, unless such registration statement is not suitable for
the sale of such shares, for example, and not by limitation, the registration of
transactions in connection with Borrower's benefit plans. Borrower shall give
Holder written notice of the opportunity to exercise such registration rights at
least ten (10) days prior to the effective date of such registration statement.

     The undersigned and each endorser, surety, and guarantor, if any, to the
extent permitted by law, hereby jointly and severally waive presentment for
payment, demand, notice of nonpayment, notice of dishonor, protest of any
dishonor, notice of protest, and protest of this Note and all other notices in
connection with the delivery, assignment, acceptance, performance, default, or
enforcement of the payment of this Note; and they agree that the liability of
the undersigned shall not in any manner be affected by any indulgence, extension
of time, renewal, waiver, or modification granted or consented to by the Holder
hereof; and they agree that additional makers, guarantors, sureties, or
endorsers may become parties hereto without affecting the liability of any of
them hereunder.
<PAGE>
 
     The Holder hereof shall not, by any act of omission or commission, be
deemed to waive any of the Holder's rights, remedies, or powers hereunder or
otherwise unless such waiver is in writing and signed by the Holder hereof, and
then only to the extent specifically set forth therein. A waiver of one event of
default shall not be construed as continuing or as a bar to or waiver of such
right, remedy, or power on a subsequent event of default.

     If the Borrower fails to pay the full amount of unpaid principal and
interest when due and payable, Borrower shall pay default interest at the rate
of ten percent (10%) plus all expenses of collection with or without suit,
including reasonable attorney's fees as may be permitted by law. The Holder may
pursue any remedies singly, successively, or together against the undersigned,
such remedies being cumulative and concurrent.

     The validity and interpretation of this Note shall be governed by the laws
of the State of California.

     Executed this        day of May, 1996.
                   ------



                                             GRIP TECHNOLOGIES, INC.  




                                             By:                      
                                                ----------------------------
                                                Sam G. Lindsay, President 



ATTEST:                         
                                


By:                            
   ---------------------------------
   James E. McCormick III, Secretary 


                                       2