Exhibit 4.15
 THIS WARRANT AND THE SECURITIES REPRESENTED BY THIS WARRANT HAVE NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933 OR THE SECURITIES ACT OF ANY STATE AND
MAY NOT BE SOLD OR TRANSFERRED UNLESS THERE IS AN EFFECTIVE REGISTRATION STATEMENT
UNDER SUCH ACTS COVERING THIS WARRANT AND THE SECURITIES REPRESENTED BY THIS
WARRANT OR PURSUANT TO AN EXEMPTION FROM THE REGISTRATION AND PROSPECTUS DELIVERY
REQUIREMENTS OF SUCH ACTS.
 BIOLARGO, INC.
 FORM OF WARRANT TO PURCHASE COMMON STOCK
(Three-Year Warrant)
 WARRANT NO. W-XXX ISSUED: XXXX , 200_
 XXXXXXX Holder Company XXXX Shares Common Stock Warrant Price Section 4
  Method of Exercise; Payment; Issuance of New Warrant
 Exhibit A Exhibit A
   1




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Stock Fully Paid; Reservation of Shares
 Fractional Shares
 Adjustment
 Adjustment for Stock Splits and Combinations
 Adjustment for Certain Dividends and Distributions
 (x)
    
    the numerator of which shall be the total
number of shares of Common Stock issued and outstanding immediately
prior to the time of such issuance; and(y)
    
    the denominator of which shall be the total
number of shares of Common Stock issued and outstanding immediately
prior to the time of such issuance plus the number of shares of Common
Stock issuable in payment of such dividend or distribution.
 Adjustment of Number of Shares Section 4(a) 4(b)
  2




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Adjustment for Reclassification, Exchange and Substitution Section 4(a) Section 4(b) Section 4(e)
 Reorganization, Mergers, Consolidations or Sales of Assets Section 4(a) Section 4(b) Section 4(d) Section 4(e)
 No Impairment
 Notice of Adjustments Section 4
  3




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The Companys Obligation to Make Payments
 Dividends and Distributions Section 4
 Redemption of Capital Stock
 Notice of Record Date
 (1)
    
    that the Company declares a dividend (or any other
distribution) on any of its capital stock (including without limitation, its
Common Stock);
 (2)
    
    that the Company repurchases or redeems any of its capital
stock (including without limitation, its Common Stock) or any rights to acquire
such capital stock;
 (3)
    
    that the Company subdivides or combines its outstanding shares
of Common Stock;
 (4)
    
    of any reclassification of the Common Stock, or of any
consolidation, merger or share exchange of the Company into or with another
entity, or of the sale of all or substantially all of the assets of the
Company;
 (5)
    
    of the involuntary or voluntary dissolution, liquidation or
winding up of the Company; or
 (6)
    
    of any offer of its Common Stock or any rights to acquire such
Common Stock for consideration paid per share of Common Stock less than the
Warrant Price then in effect.
    4




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Compliance with Securities Act; Disposition of Warrant or Common Stock
 Compliance with Securities Act Act
  Disposition of Warrant or Shares Exhibit
B
 Rights as Shareholders
 Representations and Warranties
    5




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Modification and Waiver
 Notices
 Descriptive Headings
 Governing Law
 Binding Effect on Successors
 Severability
 Lost Warrants or Stock Certificates
  6




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BIOLARGO, INC.By:
    XXXXXXName:

    Dennis Calvert, PresidentAddress:
    2603 Main Street, Suite 1155
Irvine, California 92614
Attention: Dennis Calvert
Facsimile: 949/666-7297  By:
 Print Name:
 Address:
 Federal IDor Social Security No.
  7




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EXHIBIT A
 NOTICE OF EXERCISE
  
   (Name)(Name)
  (Name)(Address)(Federal ID or Social Security No.)(Signature)(Date)




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EXHIBIT B
 NOTICE OF TRANSFER
 
 The undersigned understands that any transfer of the attached Warrant is subject to full
compliance with Federal and applicable state securities laws and other requirements, which
requirements shall be determined and which issues shall be decided by BIOLARGO, INC., in its sole
and absolute discretion, prior to consenting to and recognizing such transfer.
 
 (Signature must conform in all respects to the name
of the Holder as specified on the face of the
Warrant)(Address)
 Signed in the presence of: