CONVERTIBLE PROMISSORY NOTE

THIS NOTE AND THE SECURITIES ISSUABLE HEREUNDER HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ SECURITIES ACT ”), OR ANY STATE SECURITIES LAWS AND MAY NOT BE OFFERED, SOLD, PLEDGED, OR OTHERWISE TRANSFERRED OR DISPOSED OF UNLESS AND UNTIL THIS NOTE AND/OR SUCH SECURITIES ARE REGISTERED UNDER THE SECURITIES ACT AND APPLICABLE STATE SECURITIES LAWS OR AN EXEMPTION FROM SUCH REGISTRATION IS AVAILABLE.

FOR VALUE RECEIVED, the undersigned, GABRIEL TECHNOLOGIES CORPORATION, a Delaware corporation (“ Maker ”), promises to pay to the order of CTSL INVESTMENT, LLC, an Iowa limited liability company (“ Payee ”), the principal sum of Four Hundred Thousand Dollars ($400,000) (the “ Principal ”), plus an amount equal to 150% of the principal sum (the “ Note Obligation ”). All amounts due under this Note shall be payable as and at such time or times as are set forth in Paragraph 1 hereof. All payments on this Note shall be due and payable in lawful money of the United States of America at 675 South Fork Drive, Des Moines, Iowa 50263   (or such other place as Payee may from time to time designate in writing).

1.   Payments . The Principal and the Note Obligation shall become due and payable on December 31, 2006. Payment hereunder shall terminate the right to convert this Note. This Note shall be prepayable by the Maker as set forth in Paragraph 3 hereof.

2.   Events of Default and Remedies . In the event Maker fails to pay any amount due under this Note within ten Business Days (as hereafter defined) after such amount is due, the holder of this Note may (i) offset against this Note any sum or sums owed by the holder hereof to Maker, or (ii) proceed to protect and enforce his rights either by suit in equity and/or by action at law, or by other appropriate proceedings, whether for the specific performance of any covenant or agreement contained in this Note or to enforce any other legal or equitable right of the holder of this Note. As used herein, a “ Business Day ” is any day other than a Saturday, Sunday or a legal holiday for financial institutions in Omaha, Nebraska.

3.   Prepayments . The Principal and Note Obligation on this Note may be voluntarily prepaid in whole or in part at any time prior to conversion of this Note in accordance with Section 4 hereof. At any time prior to payment of the Principal and Note Obligation on this Note, the holder hereof shall have the option of exercising its Optional Conversion rights under Section 4(a), and Maker shall have the option of exercising its Mandatory Conversion rights under Section 4(c).

4.   Conversion .

(a)   Conversion by Payee. Unpaid Principal and Note Obligation on this Note shall be convertible at the option of Payee or other holder hereof (the “ Optional Conversion ”), at any time, in whole or in part, in lieu of and in satisfaction of such unpaid Principal and unpaid Note Obligation. This Note shall be convertible into that number of fully paid and nonassessable shares of Common Stock (as defined in Section 5) as is equal to the quotient of the unpaid Principal plus the unpaid Note Obligation divided by the applicable Conversion Price (as defined in Section 5)   in effect from time to time. Upon any Optional Conversion, the outstanding Principal and unpaid Note Obligation due under this Note shall be reduced in full by an amount equal to the number of shares of Common Stock issued upon such conversion multiplied by the applicable Conversion Price.

(b)   Conversion Procedures. If Payee desires to convert this Note into Common Stock, it shall surrender this Note to Maker at its principal executive offices, accompanied by proper instruments of transfer to Maker or in blank, accompanied by irrevocable written notice (“Optional Conversion Notice”) to Maker that Payee elects so to convert this Note and the name or names (with address) in which a certificate or certificates for Common Stock are to be issued. Maker shall, as soon as practicable after such written notice and compliance with any other conditions herein contained, deliver at such office to Payee, certificates for the number of full shares of Common Stock to which it shall be entitled. Such conversion shall be deemed to have been made as of the date of such surrender of this Note, and the person or persons entitled to receive Common Stock or other securities deliverable upon conversion shall be treated for all purposes as the record holder or holders thereof on such date.

(c)   Conversion by Maker. Notwithstanding anything to the contrary in this Note, up to the entire amount of the unpaid Principal and Note Obligation on the Note may be converted at the Maker’s election (“Mandatory Conversion”) provided: (i) no event of default has occurred and is continuing; (ii) the closing sales price of the Common Stock on its principal trading market for ten consecutive trading days (the “Trading Period”) is greater than 150% of the Maximum Conversion Price on each trading day during the Trading Period; [and (iii) the Common Stock issuable upon conversion of the then-outstanding principal and unpaid Note Obligation are included for unrestricted resale in a registration statement effective as of the date notice is given by the Maker to the holder of its election to convert the Note pursuant to this Section 4(c) (“Mandatory Conversion Notice”) and through the date the shares issuable upon Mandatory Conversion of the Note are delivered to such holder.] The Mandatory Conversion Notice must be given no later than the third trading day following the Trading Period. This Note shall be convertible into that number of fully paid and nonassessable shares of Common Stock (as defined in Section 5)   as is equal to the quotient of the unpaid Principal plus the unpaid Note Obligation divided by the applicable Conversion Price (as defined in Section 5)   in effect from time to time. Upon any Mandatory Conversion, the outstanding Principal and unpaid Note Obligation due under this Note shall be reduced in full by an amount equal to the number of shares of Common Stock issued upon such conversion multiplied by the applicable Conversion Price. If Maker desires to effect a Mandatory Conversion of all or part of this Note into Common Stock, it shall provide the Mandatory Conversion Notice to the holder of this Note. Maker shall, within five Business Days thereafter, deliver to the holder of this Note (in exchange therefor) certificates for the number of full shares of Common Stock to which it shall be entitled. Such conversion shall be deemed to have been made as of the date of the Mandatory Conversion Notice, and the person or persons entitled to receive Common Stock or other securities deliverable upon conversion shall be treated for all purposes as the record holder or holders thereof on such date.

(d)   Certain Adjustments. The applicable Conversion Price and the number of securities issuable upon conversion of this Note shall be subject to adjustment from time to time as follows:

(i)   In case Maker shall at any time after the date hereof (1) pay a dividend or make a distribution on its capital stock that is paid or made in shares of stock of Maker, (2) subdivide its outstanding shares of Common Stock into a greater number of shares or (3) combine its outstanding shares of Common Stock into a smaller number of shares, then in each such case the applicable Conversion Price in effect immediately prior thereto and the securities issuable shall be adjusted retroactively as provided below so that Payee thereafter shall be entitled to receive the number of shares of Common Stock of Maker and other shares and rights to purchase stock or other securities which Payee would have owned or have been entitled to receive after the happening of any of the events described above had this Note been converted immediately prior to the happening of such event or any record date with respect thereto. In the event of the redemption of any shares referred to in clause (1), Payee shall have the right to receive, in lieu of any such shares or rights, any cash, property or securities paid in respect of such redemption. An adjustment made pursuant to this subparagraph (i) shall become effective immediately after the record date in the case of a dividend or distribution and shall become effective immediately after the effective date in the case of a subdivision or combination.

(ii)   Whenever the Conversion Price is adjusted as provided above, Maker shall compute the adjusted Conversion Price in accordance herewith and mail to Payee a notice stating that the Conversion Price has been adjusted and setting forth the adjusted Conversion Price.

(iii)   In the event that at any time, as a result of any adjustment made pursuant to this Section, Pay