Exhibit 10.4


 


June 29, 2021


 


Shelter Acquisition Corporation I

6 Midland Street #1726

Quogue, New York 11959


 


		Re:	Initial Public Offering



 


Ladies and Gentlemen:


 


This letter (this “Letter
Agreement”) is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”)
entered into by and between Shelter Acquisition Corporation I, a Delaware corporation (the “Company”), and Citigroup
Global Markets, Inc. and Wells Fargo Securities, LLC, as representatives (the “Representatives”) of the several
underwriters (the “Underwriters”), relating to an underwritten initial public offering (the “Public
Offering”) of 23,000,000 of the Company’s units (including 3,000,000 units that may be purchased pursuant to the Underwriters’
option to purchase additional units, the “Units”), each comprising of one share of the Company’s Class
A common stock, par value $0.0001 per share (the “Common Stock”), and one-half of one redeemable warrant (each
whole warrant, a “Warrant”). Each Warrant entitles the holder thereof to purchase one share of Common Stock
at a price of $11.50 per share, subject to adjustment. The Units will be sold in the Public Offering pursuant to a registration statement
on Form S-1 and a prospectus (the “Prospectus”) filed by the Company with the U.S. Securities and Exchange Commission
(the “Commission”). Certain capitalized terms used herein are defined in paragraph 1 hereof.


 


In order to induce the Company
and the Underwriters to enter into the Underwriting Agreement and to proceed with the Public Offering and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, Shelter Sponsor LLC (the “Sponsor”)
and each of the undersigned (each, an “Insider” and, collectively, the “Insiders”)
hereby agree with the Company as follows:


 


1. Definitions.
As used herein, (i) “Business Combination” shall mean a merger, capital stock exchange, asset acquisition,
stock purchase, reorganization or similar business combination, involving the Company and one or more businesses; (ii)
“Founder Shares” shall mean the 5,750,000 shares of Class B common stock of the Company, par value $0.0001
per share, outstanding prior to the consummation of the Public Offering; (iii) “Private Placement
Warrants” shall mean the warrants to purchase shares of Common Stock of the Company that will be acquired by the
Sponsor for an aggregate purchase price of $6,250,000 (or up to $6,850,000 if the Underwriters exercise their option to purchase
additional Units) or $1.00 per Warrant, in a private placement that shall close simultaneously with the consummation of the Public
Offering (including Common Stock issuable upon conversion thereof); (iv) “Public Stockholders” shall mean
the holders of Common Stock included in the Units issued in the Public Offering; (v) “Public Shares” shall
mean the Common Stock included in the Units issued in the Public Offering; (vi) “Trust Account” shall mean
the trust account into which a portion of the net proceeds of the Public Offering and the sale of the Private Placement Warrants
shall be deposited; (vii) “Transfer” shall mean the (a) sale of, offer to sell, contract or agreement to
sell, hypothecate, pledge, grant of any option to purchase or otherwise dispose of or agreement to dispose of, directly or
indirectly, or establishment or increase of a put equivalent position or liquidation with respect to or decrease of a call
equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, and the rules and
regulations of the Commission promulgated thereunder with respect to, any security, (b) entry into any swap or other arrangement
that transfers to another, in whole or in part, any of the economic consequences of ownership of any security, whether any such
transaction is to be settled by delivery of such securities, in cash or otherwise, or (c) public announcement of any intention to
effect any transaction specified in clause (a) or (b); and (viii) “Charter” shall mean the Company’s
Amended and Restated Certificate of Incorporation, as the same may be amended from time to time.


 






    


     


    

 


2.  Representations
and Warranties.


 


(a)
The Sponsor and each Insider, with respect to itself, herself or himself, represent and warrant to the Company that it, she or he
has the full right and power, without violating any agreement to which it, she or he is bound (including, without limitation, any
non-competition or non-solicitation agreement with any employer or former employer), to enter into this Letter Agreement. Each
Insider that is a Director or Officer represents and warrants on behalf of himself or herself that she or he has the full right and
power without violating any agreement to which it, she or he is bound (including, without limitation, any non-competition or
non-solicitation agreement with any employer or former employer), to enter into this Letter Agreement to serve as an officer of the
Company and/or a director on the Company’s Board of Directors (the “Board”), as applicable, and each
such Insider hereby consents to being named in the Prospectus, road show and any other materials as an officer and/or director of
the Company, as applicable.


 


(b)
Each Insider that is a natural person represents and warrants, with respect to herself or himself, that such Insider’s
biographical information furnished to the Company (including any such information included in the Prospectus) is true and accurate
in all material respects and does not omit any material information with respect to such Insider’s background; and such
Insider’s questionnaire furnished to the Company is true and accurate in all material respects. Each such Insider represents
and warrants that such Insider is not subject to or a respondent in any legal action for, any injunction, cease-and-desist order or
order or stipulation to desist or refrain from any act or practice relating to the offering of securities in any jurisdiction; such
Insider has never been convicted of, or pleaded guilty to, any crime (i) involving fraud, (ii) relating to any financial transaction
or handling of funds of another person, or (iii) pertaining to any dealings in any securities and such Insider is not currently a
defendant in any such criminal proceeding; and such Insider has never been suspended or expelled from membership in any securities
or commodities exchange or association or had a securities or commodities license or registration denied, suspended or revoked.


 


3. Business
Combination Vote. It is acknowledged and agreed that the Company shall not enter into a definitive agreement regarding a
proposed Business Combination without the prior consent of the Sponsor. The Sponsor and each Insider, with respect to itself,
herself or himself, agrees that if the Company seeks stockholder approval of a proposed initial Business Combination, then in
connection with such proposed initial Business Combination, it, she or he, as applicable, shall vote all Founder Shares and any
Public Shares held by it, her or him, as applicable, in favor of such proposed initial Business Combination (including any proposals
recommended by the Board in connection with such Business Combination) and not redeem any Public Shares held by it, her or him, as
applicable, in connection with such stockholder approval.


 


4. Failure to Consummate
a Business Combination; Trust Account Waiver.


 


(a) The
Sponsor and each Insider that is a natural person hereby agree, with respect to itself, herself or himself, that in the event that the
Company fails to consummate its initial Business Combination within the time period set forth in the Charter, the Sponsor and each such
Insider shall take all reasonable steps to cause the Company to (i) cease all operations except for the purpose of winding up; (ii) as
promptly as reasonably possible but not more than 10 business days thereafter, redeem 100% of the Public Shares, at a per-share price,
payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the
Trust Account and not previously released to the Company to pay income taxes (less up to $100,000 of interest to pay dissolution expenses),
divided by the number of then outstanding Public Shares, which redemption will completely extinguish Public Stockholders’ rights
as stockholders (including the right to receive further liquidation distributions, if any); and (iii) as promptly as reasonably possible
following such redemption, subject to the approval of the Company’s remaining stockholders and the Board, liquidate and dissolve,
subject in the case of clauses (ii) and (iii) to the Company’s obligations under Delaware law to provide for claims of creditors
and in all cases subject to the other requirements of applicable law. The Sponsor and each Insider agree not to propose any amendment
to the Charter (i) that would modify the substance or timing of the Company’s obligation to provide holders of the Public Shares
the right to have their shares redeemed in connection with an initial Business Combination or to redeem 100% of the Public Shares if the
Company does not complete an initial Business Combination within the required time period set forth in the Charter or (ii) with respect
to any provision relating to the rights of holders of Public Shares unless the Company provides its Public Stockholders with the opportunity
to redeem their Public Shares upon approval of any such amendment at a per-share price, payable in cash, equal to the aggregate amount
then on deposit in the Trust Account, including interest earned on the funds held in the Trust Account and not previously released to
the Company to pay taxes, if any, divided by the number of then-outstanding Public Shares.


 


(b) The
Sponsor and each Insider, with respect to itself, herself or himself, acknowledges that it, she or he has no right, title, interest or
claim of any kind in or to any monies held in the Trust Account of the Company as a result of any liquidation of the Company with respect
to the Founder Shares held by it, her or him, if any. The Sponsor and each of the Insiders hereby further waive, with respect to any Founder
Shares and Public Shares held by it, her or him, as applicable, any redemption rights it, she or he may have in connection with the consummation
of a Business Combination, including, without limitation, any such rights available in the context of a stockholder vote to approve such
Business Combination or a stockholder vote to approve an amendment to the Charter (i) that would modify the substance or timing of the
Company’s obligation to provide holders of the Public Shares the right to have their shares redeemed in connection with an initial
Business Combination or to redeem 100% of the Public Shares if the Company has not consummated an initial Business Combination within
the time period set forth in the Charter or (ii) with respect to any provision relating to the rights of holders of Public Shares (although
the Sponsor and the Insiders shall be entitled to liquidation rights with respect to any Public Shares they hold if the Company fails
to consummate a Business Combination within the required time period set forth in the Charter).


 






    2


     


    

 


5. Lock-up; Transfer Restrictions.


 


(a) The
Sponsor and the Insiders agree that they shall not Transfer any Founder Shares (the “Founder Shares Lock-up”)
until the earliest of (A) one year after the completion of an initial Business Combination and (B) following the completion of an initial
Business Combination, the date on which the Company completes a liquidation, merger, capital stock exchange, reorganization or other similar
transaction that results in all of the Company’s stockholders having the right to exchange their Common Stock for cash, securities
or other property (the “Founder Shares Lock-up Period”). Notwithstanding the foregoing, if, subsequent to a
Business Combination, the closing price of the Common Stock equals or exceeds $12.00 per share (as adjusted for stock splits, stock dividends,
reorganizations, recapitalizations and the like) for any 20 trading days within a 30-trading day period commencing at least 150 days after
the Company’s initial Business Combination, the Founder Shares shall be released from the Founder Shares Lock-up.


 


(b) The
Sponsor and Insiders agree that they shall not effectuate any Transfer of Private Placement Warrants or Common Stock underlying such warrants
until 30 days after the completion of an initial Business Combination.


 


(c) Notwithstanding
the provisions set forth in paragraphs 5(a) and (b), Transfers of the Founder Shares, Private Placement Warrants and Common
Stock underlying the Private Placement Warrants are permitted (a) to the Company’s officers or directors, any affiliates or family
members of any of the Company’s officers or directors, any members or partners of the Sponsor or their affiliates, any affiliates
of the Sponsor, or any employees of such affiliates; (b) in the case of an individual, by gift to a member of one of the individual’s
immediate family or to a trust, the beneficiary of which is a member of the individual’s immediate family, an affiliate of such
person or to a charitable organization; (c) in the case of an individual, by virtue of laws of descent and distribution upon death of
the individual; (d) in the case of an individual, pursuant to a qualified domestic relations order; (e) by private sales or transfers
made in connection with the consummation of a Business Combination at prices no greater than the price at which the Founder Shares, Private
Placement Warrants or Common Stock, as applicable, were originally purchased; (f) by virtue of the laws of Delaware or the Sponsor’s
organizational documents upon liquidation or dissolution of the Sponsor; (g) to the Company for no value for cancellation in connection
with the consummation of an initial Business Combination; (h) in the event of the Company’s liquidation prior to the completion
of an initial Business Combination; or (i) in the event of the Company’s completion of a liquidation, merger, share exchange or
other similar transaction which results in all of the Company’s Public Stockholders having the right to exchange their Common Stock
for cash, securities or other property subsequent to the completion of an initial Business Combination; provided, however,
that in the case of clauses (a) through (f) these permitted transferees must enter into a written agreement agreeing to be bound by these
transfer restrictions.


 


(d) During
the period commencing on the effective date of the Underwriting Agreement and ending 180 days after such date, the Sponsor and each Insider
shall not, without the prior written consent of the Representatives, Transfer any Units, Common Stock, Warrants or any other securities
convertible into, or exercisable or exchangeable for, Common Stock held by it, her or him, as applicable, subject to certain exceptions
enumerated in Section 4(h) of the Underwriting Agreement.


 


6.  Remedies. The
Sponsor and each of the Insiders hereby agree and acknowledge that (i) each of the Underwriters and the Company would be irreparably
injured in the event of a breach by the Sponsor or such Insider of its, her or his obligations, as applicable under paragraphs
3, 4, 5, 7, 10 and 11, (ii) monetary damages may not be an adequate remedy for such breach
and (iii) the non-breaching party shall be entitled to seek injunctive relief, in addition to any other remedy that such party may
have in law or in equity, in the event of such breach.


 


7. Payments by the Company.
Except as disclosed in the Prospectus, neither the Sponsor nor any affiliate of the Sponsor nor any director or officer of the Company
nor any affiliate of the officers shall receive from the Company any finder’s fee, reimbursement, consulting fee, monies in respect
of any payment of a loan or other compensation prior to, or in connection with any services rendered in order to effectuate the consummation
of the Company’s initial Business Combination (regardless of the type of transaction that it is).


 


8. Director and
Officer Liability Insurance. The Company will maintain an insurance policy or policies providing directors’ and
officers’ liability insurance, and each Insider that is a director or officer shall be covered by such policy or policies, in
accordance with its or their terms, to the maximum extent of the coverage available for any of the Company’s directors or
officers.


 


9. Termination.
This Letter Agreement shall terminate on the earlier of (i) the expiration of the Founder Shares Lock-up Period and (ii) the liquidation
of the Company.


 






    3


     


    

 


10. Indemnification.
In the event of the liquidation of the Trust Account upon the failure of the Company to consummate its initial Business Combination within
the time period set forth in the Charter, the Sponsor (the “Indemnitor”) agrees to indemnify and hold harmless
the Company against any and all loss, liability, claim, damage and expense whatsoever (including, but not limited to, any and all legal
or other expenses reasonably incurred in investigating, preparing or defending against any litigation, whether pending or threatened)
to which the Company may become subject as a result of any claim by (i) any third party for services rendered or products sold to the
Company (except for the Company’s independent auditors) or (ii) any prospective target business with which the Company has discussed
entering into a transaction agreement (a “Target”); provided, however, that such indemnification
of the Company by the Indemnitor (x) shall apply only to the extent necessary to ensure that such claims by a third party for services
rendered or products sold to the Company or a Target do not reduce the amount of funds in the Trust Account to below the lesser of (i)
$10.00 per Public Share and (ii) the actual amount per Public Share held in the Trust Account as of the date of the liquidation of the
Trust Account if less than $10.00 per Public Share due to reductions in the value of the trust assets, in each case net of interest that
may be withdrawn to pay the Company’s tax obligations, (y) shall not apply to any claims by a third party or Target who executed
a waiver of any and all rights to the monies held in the Trust Account (whether or not such waiver is enforceable) and (z) shall not
apply to any claims under the Company’s indemnity of the Underwriters against certain liabilities, including liabilities under
the Securities Act of 1933, as amended. The Indemnitor shall have the right to defend against any such claim with counsel of its choice
reasonably satisfactory to the Company if, within 15 days following written receipt of notice of the claim to the Indemnitor, the Indemnitor
notifies the Company in writing that it shall undertake such defense.


 


11. Forfeiture of Founder
Shares. To the extent that the Underwriters do not exercise their option to purchase additional Units within 45 days from the date
of the Prospectus in full (as further described in the Prospectus), the Sponsor agrees to automatically surrender to the Company for
no consideration, for cancellation at no cost, an aggregate number of Founder Shares so that the number of Founder Shares will equal
20% of the sum of the total number of Common Stock and Founder Shares outstanding at such time. The Sponsor and Insiders further agree
that to the extent that the size of the Public Offering is increased or decreased, the Company will effect a stock split, stock dividend,
reverse stock split or stock repurchase, as applicable, with respect to the Founder Shares immediately prior to the consummation of the
Public Offering in such amount as to maintain the number of Founder Shares at 20% of the sum of the total number of Common Stock and
Founder Shares outstanding at such time.


 


12. Entire
Agreement. This Letter Agreement constitutes the entire agreement and understanding of the parties hereto in respect of the
subject matter hereof and supersedes all prior understandings, agreements, or representations by or among the parties hereto,
written or oral, to the extent they relate in any way to the subject matter hereof or the transactions contemplated hereby. This
Letter Agreement may not be changed, amended, modified or waived (other than to correct a typographical error) as to any particular
provision, except by a written instrument executed by all parties hereto.


 


13. Assignment.
No party hereto may assign either this Letter Agreement or any of its rights, interests, or obligations hereunder without the prior
written consent of the other parties. Any purported assignment in violation of this paragraph shall be void and ineffectual and
shall not operate to transfer or assign any interest or title to the purported assignee. This Letter Agreement shall be binding on
the Sponsor, each of the Insiders and each of their respective successors, heirs, personal representatives and assigns and permitted
transferees.


 


14. Counterparts.
This Letter Agreement may be executed in any number of counterparts, and each of such counterparts shall for all purposes be deemed
to be an original, and all such counterparts shall together constitute but one and the same instrument. Signatures to this Agreement
transmitted via facsimile or e-mail shall be valid and effective to bind the party so signing (including any electronic signature
covered by the U.S. federal ESIGN Act of 2000, Uniform Electronic Transactions Act, the Electronic Signatures and Records Act or
other applicable law, e.g., www.docusign.com).


 


15. Effect of Headings.
The paragraph headings herein are for convenience only and are not part of this Letter Agreement and shall not affect the interpretation
thereof.


 


16. Severability.
This Letter Agreement shall be deemed severable, and the invalidity or unenforceability of any term or provision hereof shall not
affect the validity or enforceability of this Letter Agreement or of any other term or provision hereof. Furthermore, in lieu of any
such invalid or unenforceable term or provision, the parties hereto intend that there shall be added as a part of this Letter
Agreement a provision as similar in terms to such invalid or unenforceable provision as may be possible and be valid and
enforceable.


 


17. Governing
Law. This Letter Agreement shall be governed by and construed and enforced in accordance with the laws of the State of New York,
without giving effect to conflicts of law principles that would result in the application of the substantive laws of another
jurisdiction. The parties hereto (i) all agree that any action, proceeding, claim or dispute arising out of, or relating in any way
to, this Letter Agreement shall be brought and enforced in the courts of New York City, in the State of New York, and irrevocably
submit to such jurisdiction and venue, which jurisdiction and venue shall be exclusive, and (ii) waive any objection to such
exclusive jurisdiction and venue or that such courts represent an inconvenient forum.


 


18. Notices. Any notice,
consent or request to be given in connection with any of the terms or provisions of this Letter Agreement shall be in writing and shall
be sent by express mail or similar private courier service, by certified mail (return receipt requested), by hand delivery or facsimile
transmission.


 


[Signature Page Follows]









    4


     


    

 


	 	Sincerely,
	 	 
		SHELTER SPONSOR LLC
	 	 
		By:	/s/ Christopher Keber
		Name:	Christopher Keber
		Title:	Manager



  


[Signature Page to Insider Letter Agreement]


 



     


     


    




 


		/s/ John R. Chandler
		John R. Chandler
	 	 
		/s/ Danion Fielding
		Danion Fielding
	 	 
		/s/ Christopher Keber
		Christopher Keber
	 	 
		/s/ Anthony Foxx
		Anthony Foxx
	 	 
		/s/ Brad Briner
		Brad Briner

                                 

	 	 
		/s/ Clelia Peters
		Clelia Peters
	 	 
		/s/ Christopher Bledsoe
		Christopher Bledsoe
	 	 
		/s/ Erin Lantz
		Erin Lantz
	 	 
		/s/ Kenneth Hubbard
		Kenneth Hubbard
	 	 
		/s/ Chris Gough
		Chris Gough
	 	 
		/s/ David Panton
		David Panton
	 	 
		/s/ Kathleen Collins
		Kathleen Collin
	 	 
		/s/ Sonny Kalsi
		Sonny Kalsi
	 	 
		/s/ Scott Wesson
		Scott Wesson
	 	 
		/s/ Sean Muellers
		Sean Muellers
	 	 
		/s/ Whitney Topping
		Whitney Topping


 


[Signature Page to Insider Letter Agreement]


 



     


     


    

 


	 	
    SPAC OPPORTUNITY PARTNERS

    INVESTMENT SUB, LLC

	 	 
	 	/s/ Ronald Coombs
	 	Name: Ronald Coombs
	 	Title: Chief Financial Officer
	 	 
	 	KEEFE, BRUYETTE & WOODS, INC.
	 	 
	 	/s/ Peter J. Wirth
	 	Name: Peter J. Wirth
	 	Title: Executive Vice President
	 	 
	 	ALMANAC REALTY PUBLIC 
	 	SECURITIES, L.P.
	 	 
	 	/s/ Matthew J. Wolpert
	 	Name: Matthew J. Wolpert
	 	Title: Managing Director



 


[Signature Page to Insider Letter Agreement]


 






     


     


    

 





	 	Acknowledged and Agreed:
	 	 
	 	SHELTER ACQUISITION CORPORATION I
	 	 	 
	 	By:	/s/ Christopher
    Keber
	 	Name:	Christopher Keber
	 	Title:	Chief Executive Officer



 


[Signature Page to Insider Letter Agreement]