| Item 1. | Security and Issuer |
| (a) | Title of Class of Securities:
Ordinary Shares, par value NIS 1.5 per share |
| (b) | Name of Issuer:
CollPlant Biotechnologies Ltd |
| (c) | Address of Issuer's Principal Executive Offices:
4 Oppenheimer St, Weizmann Science Park, Rehovot,
ISRAEL
, 7670104. |
| Item 2. | Identity and Background |
|
| (a) | The Waterproof Partnership, Ltd., The Loewenbaum 1992 Trust, The Loewenbaum Residence Trust FBO Anna Loewenbaum and The Elizabeth Scott Loewenbaum 1992 Trust are collectively referred to as the "Reporting Entities" and each as a "Reporting Entity." George Walter Loewenbaum, Elizabeth S. Loewenbaum and Lilian S. Loewenbaum are referred to herein as the "Individual Filers" and each, an "Individual Filer". The Individual Filers and the Reporting Entities are collectively referred to herein as the "Reporting Persons".
The Waterproof Partnership, Ltd., a holding company, is a Texas limited partnership, with George Walter Loewenbaum and Lilian S. Loewenbaum serving as general partners. The Loewenbaum 1992 Trust, a holding company, is a Texas trust, with George Walter Loewenbaum and Lilian S. Loewenbaum serving as trustees. The Loewenbaum Residence Trust FBO Anna Loewenbaum, a holding company, is a Texas trust, with George Walter Loewenbaum and Lilian S. Loewenbaum serving as trustees. The Elizabeth Scott Loewenbaum 1992 Trust, a holding company, is a Texas trust, with George Walter Loewenbaum and Lilian S. Loewenbaum serving as trustees.
Effective as of August 19, 2026, Nachum Shamir and the Reporting Persons confirmed and agreed they are not acting as a group, and Nachum Shamir's holdings have been removed from this filing. Effective as of August 20, 2026, Patrick Chalmers, Reginald J. Hargrove and the Reporting Persons confirmed and agreed they are not acting as a group, and the holdings of Patrick Chalmers and Reginald J. Hargrove have been removed from this filing. |
| (b) | The address of each Reporting Person is 1000 Westbank Dr, Ste #2A, Austin, TX 78746. George Walter Loewenbaum, Elizabeth S. Loewenbaum and Lilian S. Loewenbaum are citizens of the United States and their current occupations are individual private investors. |
| (c) | Refer (b) above |
| (d) | During the last five years, none of the Reporting Persons nor any general partner or trustee of the Reporting Entities (a) has been convicted in a criminal proceeding (excluding traffic violations and similar misdemeanors), or (b) was a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violations with respect to such laws. |
| (e) | Refer (d) above |
| (f) | Refer (b) above |
| Item 3. | Source and Amount of Funds or Other Consideration |
| | The information concerning the ownership of Ordinary Shares of the Reporting Persons set forth on the cover pages hereto is expressly incorporated by reference herein. |
| Item 4. | Purpose of Transaction |
| | On June 29, 2026, The Loewenbaum 1992 Trust entered into a Securities Purchase Agreement with the Issuer for the purchase of 1,764,706 Ordinary Shares, Series A Warrants to purchase 1,764,706 Ordinary Shares (the "Series A Warrants"), and Series B Warrants to purchase 3,529,412 Ordinary Shares (the "Series B Warrants" and, together with the Series A Warrants, the "Warrants"). The transaction was completed on July 6, 2026.
The Series A Warrants have an exercise price of $0.34 per share and are exercisable as of July 29, 2026, the date of shareholder approval (the "Shareholder Approval Date"). The Series A Warrants expire on July 16, 2028. The Series B Warrants have an exercise price of $0.34 per share and are exercisable as of the Shareholder Approval Date. The Series B Warrants expire on July 16, 2031. The Loewenbaum 1992 Trust is only permitted to exercise the Warrants up to a beneficial ownership limitation of 24.99% (the "Beneficial Ownership Limitation") which limitation is based on holdings of the other Reporting Persons.
Effective August 20, 2026, The Lowenbaum 1992 Trust and the Issuer memorialized a transfer of funds whereby The Lowenbaum 1992 Trust transferred funds in the amount of the aggregate exercise price of the Series B Warrants. No Warrants were exercised, and the funds are held in abeyance until further notice from The Lowenbaum 1992 Trust.
The acquisitions of Ordinary Shares and Warrants by the Reporting Persons was for investment purposes.
The Reporting Persons intend to review their investment in the Issuer on a continuing basis and, depending upon the price of and other market conditions relating to the Ordinary Shares or other securities of the Issuer, subsequent developments affecting the Issuer, the Issuer's business and prospects, other investment and business opportunities available to the Reporting Persons, general stock market and economic conditions, tax considerations, and other factors deemed relevant, may form a plan or proposal to take any of the actions specified in clauses (a) through (j) of Item 4 of Schedule 13D, in which case the Reporting Persons will file an amendment to this Schedule 13D. No Reporting Person has any present plan or proposal which would relate to or result in any of the matters set forth in subparagraphs (a) - (j) of Item 4 of Schedule 13D except as set forth herein or such as would occur upon or in connection with completion of, or following, any of the actions discussed herein. |
| Item 5. | Interest in Securities of the Issuer |
| (a) | The information concerning the ownership of the Ordinary Shares of the Reporting Persons set forth on the cover pages hereto is expressly incorporated by reference herein. To the best knowledge of the Reporting Persons, as of August 19, 2026, there were 18,908,207 Ordinary Shares outstanding, as set forth in the Proxy Statement filed as Exhibit 99.1 to the Form 6-K filed by the Issuer with the SEC on July 28, 2026. The calculations of percentages in this Schedule 13D are based on 20,570,548 Ordinary Shares outstanding as of August 19, 2026, which is based on the 18,908,207 Ordinary Shares as set forth by the Issuer, plus 1,662,341 Ordinary Shares, which is the approximate maximum number of Ordinary Shares obtainable upon exercise of the Warrants up to the Beneficial Ownership Limitation.
Collectively, the Reporting Persons beneficially own in the aggregate 5,140,580 Ordinary Shares, representing 24.99% of the total outstanding Ordinary Shares (including approximately 1,662,341 Ordinary Shares that may be issued to the Reporting Persons within 60 days upon the exercise of options and warrants up to the Beneficial Ownership Limitation). |
| (b) | The information concerning the ownership of Ordinary Shares of the Reporting Persons set forth on the cover pages hereto is expressly incorporated by reference herein. |
| (c) | Not applicable. |
| (d) | Except as listed in Item 5(a), to the best knowledge of the Reporting Persons, no person other than the Reporting Persons has the right to receive, or the power to direct the receipt of dividends from, or the power to direct the receipt of proceeds of the sale of the shares of Common Stock beneficially owned by the Reporting Persons. |
| (e) | Not applicable. |
| Item 6. | Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer |
| | The Reporting Persons have entered into a Joint Filing Agreement, dated August 21, 2026, a copy of which is attached hereto as Exhibit 1 to this Schedule 13D and is incorporated herein by reference. |
| Item 7. | Material to be Filed as Exhibits. |
| | 1. Joint Filing Agreement dated August 21, 2026. |
