Exhibit 4.1


 


	NUMBER

U-	UNITS



 


SPECIMEN UNIT CERTIFICATE


 


SEE REVERSE FOR CERTAIN DEFINITIONS


 


CUSIP 822821 203


 


SHELTER ACQUISITION CORPORATION I


 


UNITS CONSISTING OF ONE SHARE OF CLASS A
COMMON STOCK AND ONE-THIRD OF ONE

WARRANT TO PURCHASE ONE SHARE OF CLASS A COMMON STOCK


 


THIS CERTIFIES THAT____________________is
the owner of___________Units.


 


Each Unit (“Unit”)
consists of one (1) share of Class A common stock, par value $0.0001 per share (“Common Stock”),
of Shelter Acquisition Corporation I, a Delaware corporation (the “Company”), and one-third (1/3) of
one warrant (each whole warrant, a “Warrant”).  Each Warrant entitles the holder to purchase one
(1) share (subject to adjustment) of Common Stock for $11.50 per share (subject to adjustment).  Each Warrant will become
exercisable thirty (30) days after the Company’s completion of a merger, capital stock exchange, asset acquisition,
stock purchase, reorganization or other similar business combination with one or more businesses (each a “Business
Combination”), and will expire unless exercised before 5:00 p.m., New York City Time, on the date that is five (5) years
after the date on which the Company completes its initial Business Combination, or earlier upon redemption or liquidation (the
“Expiration Date”).  The Common Stock and Warrants comprising the Units represented by this certificate
are not transferable separately prior to               ,
2021, unless Citigroup Global Markets Inc. and Wells Fargo Securities, LLC elect to allow earlier separate trading, subject to
the Company’s filing with the Securities and Exchange Commission of a Current Report on Form 8-K containing an audited
balance sheet reflecting the Company’s receipt of the gross proceeds of the Company’s initial public offering and issuing
a press release announcing when separate trading will begin. No fractional warrants will be issued upon separation of the Units
and only whole warrants are exercisable.  The terms of the Warrants are governed by a Warrant Agreement, dated as of ,
2021, between the Company and Continental Stock Transfer & Trust Company, as Warrant Agent, and are subject to the terms
and provisions contained therein, all of which terms and provisions the holder of this certificate consents to by acceptance hereof. 
Copies of the Warrant Agreement are on file at the office of the Warrant Agent at 1 State Street, 30th Floor, New York, New York
10004, and are available to any Warrant holder on written request and without cost.


 


Upon the consummation of the Business Combination,
the Units represented by this certificate will automatically separate into the Class A Common Stock and Warrants comprising such
Units.


 


This certificate is not valid unless countersigned
by the Transfer Agent and Registrar of the Company.


 


This certificate shall be governed by and
construed in accordance with the internal laws of the State of New York.


 


Witness the facsimile signatures of its
duly authorized officers.


 


	 	 	 
	Chief Executive Officer	 	Chief Financial Officer



 



     


     


    

 


Shelter Acquisition Corporation I


 


The Company will furnish without charge
to each unitholder who so requests, a statement of the powers, designations, preferences and relative, participating, optional
or other special rights of each class of stock or series thereof of the Company and the qualifications, limitations, or restrictions
of such preferences and/or rights.


 


The following abbreviations, when used in
the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable
laws or regulations: 


 


	TEN COM	—	as tenants in common	UNIF GIFT MIN ACT	—	 	Custodian	 
	TEN ENT	—	as tenants by the entireties	 	 	(Cust)	 	(Minor)
	JT TEN	—	as joint tenants with right of survivorship and not as tenants in common	 	 	 

                                                                                                         under Uniform Gifts to Minors Act

                                                                                 

	 	 	 	 	 	(State)


 


Additional abbreviations may also be used
though not in the above list.


 


For value received,________________hereby sells, assigns
and transfers unto                    


 


PLEASE INSERT
SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE 


 


(PLEASE
PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)


 


________________________________________Units
represented by the within Certificate, 


 


and does hereby irrevocably constitute
and appoint__________________________Attorney


 


to transfer the said Units on the books
of the within named Company with full power of


 


substitution in the premises.

 






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	Dated____________
	 	 Notice: The signature to this assignment must correspond with the name as written upon the face of the certificate in every particular, without alteration or enlargement or any change whatever.


 


	Signature(s) Guaranteed:	 	 
	 	 	 
	THE SIGNATURE(S) MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM, PURSUANT TO S.E.C. RULE 17Ad-15 OR ANY SUCCESSOR RULES).


 


In each case, as more fully described in the Company’s
final prospectus dated       , 2021, the holder(s) of this certificate shall be entitled to receive a pro-rata portion
of certain funds held in the trust account established in connection with the Company’s initial public offering only in the
event that (i) the Company redeems the shares of Common Stock sold in its initial public offering and liquidates because it
does not consummate an initial business combination within the period of time set forth in the Company’s amended and restated
certificate of incorporation, as the same may be amended from time to time, (ii) the Company redeems the shares of Common
Stock sold in its initial public offering in connection with a stockholder vote to amend the Company’s amended and restated
certificate of incorporation (A) that would modify the substance or timing of the Company’s obligation to provide holders
of the Common Stock the right to have their shares redeemed in connection with the Company’s initial business combination
or to redeem 100% of the Common Stock if the Company does not complete its initial business combination within the time period
set forth therein or (B) with respect to any other provision relating to the rights of holders of Common Stock, or (iii) if
the holder(s) seek(s) to redeem for cash his, her or its respective shares of Common Stock in connection with a tender
offer (or proxy solicitation, solely in the event the Company seeks stockholder approval of the proposed initial business combination)
setting forth the details of a proposed initial business combination.  In no other circumstances shall the holder(s) have
any right or interest of any kind in or to the trust account.


 


 


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