Document:

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                                                                   Exhibit 10.45

                            ASSET PURCHASE AGREEMENT

     THIS ASSET PURCHASE AGREEMENT (the "Agreement") made and entered into this
31st day of December 2001 by and between BELFIBER, CO., a Virginia corporation,
(the "Buyer") and AIR PURATOR CORPORATION, a Delaware corporation (the
"Seller").

                                   WITNESSETH:

     WHEREAS, Seller is engaged in the manufacturing of nonwoven fabric filter
products (the "Business"); and

     WHEREAS, Seller wishes to sell and transfer to Buyer certain assets,
properties and business of Seller and to retain certain of its assets and
liabilities pursuant to and in accordance with the terms and conditions of this
Agreement; and

     WHEREAS, Buyer wishes to acquire certain assets, properties and business of
the Seller, pursuant to and in accordance with the terms and conditions of this
Agreement.

     NOW, THEREFORE, for and in consideration of the promises and mutual
covenants contained herein, and other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the parties do hereby
mutually agree as follows:

     1. Purchase and Sale of Assets. At the Closing, as hereinafter defined,
        ---------------------------
Seller shall sell, assign, transfer and deliver to Buyer all right, title and
interest of Seller in and to the following:

          a) any and all rights Seller possesses with regard to the name "Air
Purator Corporation";

          b) any and all inventory, including, but not limited to, finished
goods, work-in process, raw materials, supplies and other materials
(collectively, the "Inventory") possessed by Seller, as such Inventory exists
(determined in accordance with Section 6 hereof) as of the Closing ;

          c) the intellectual property owned by Seller and specified on Exhibit
1 attached hereto and made a part hereof;

          d) to the extent transferable, all approvals, permits, product
licenses and other governmental authorizations and approvals (federal, state and
local) relating to the Assets, as such items are specified on Exhibit 1;

          e) Seller's customer list, as specified on Exhibit 1; and

          f) certain fixed assets, as specified on Exhibit 1.

(collectively the "Assets").

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     Subject to the terms and conditions of this Agreement, Seller shall sell,
assign, transfer and deliver the Assets to Buyer, and Buyer shall purchase the
Assets, for the consideration set forth in Section 4 below.

     2. Excluded Assets. The Assets shall exclude any and all assets owned or
        ---------------
used by Seller that are not specifically identified in Section 1 above on
Exhibit 1.

     3. Liabilities and Obligations to be Assumed Prior to Closing. Except as
        ----------------------------------------------------------
set forth on Exhibit 2 attached hereto and made a part hereof, Buyer shall not
assume, pay or discharge, and shall not be liable for, any debts, obligations,
responsibilities or liabilities of Seller, or any claim, action or suit relating
thereto, whether now existing or hereafter arising, known or unknown, contingent
or absolute, relating to or arising from the period prior to the Closing,
including, by way of example only and not in limitation thereof, Seller's
liabilities in connection with any of Seller's contractual obligations; Seller's
account payables; Seller's tax liabilities of any kind or nature whatsoever; or
any liabilities of Seller of any other kind or description whether accrued,
absolute, contingent or otherwise (collectively the "Liabilities"). Seller shall
remain fully and completely liable for all of Liabilities. From and after the
Closing, Buyer shall be solely responsible for any and all debts, obligations,
responsibilities and liabilities relating to or arising from the Assets or the
business related thereto.

     4. Purchase Price. In consideration of the sale, assignment, transfer and
        --------------
delivery to Buyer of the Assets, and as payment in full therefore, subject to
the adjustment provisions of Section 7 hereof, and upon the terms and subject to
the conditions contained in this Agreement, Buyer shall pay to Seller the sum of
Four Hundred and Seventy-Five Thousand Dollars ($475,000) (the "Purchase Price")
for the Assets. Three Hundred and Seventy-Five Thousand Dollars ($375,000) of
the Purchase Price shall be paid in cash or by debt instrument at the Closing.
Buyer shall execute a promissory note in the form attached hereto as Exhibit 3
(the "Note") for the balance of the Purchase Price.

     5. Payment of Purchase Price. At the Closing, Buyer shall pay any cash
        -------------------------
portion of the Purchase Price to Seller by wire transfer in immediately
available funds, and shall deliver any and all debts instruments, including but
not limited to the Note, to Seller. Any additional Purchase Price required to be
paid pursuant to Section 7 hereof shall be paid in accordance therewith.

     6. Determination of Inventory. The quantity and valuation of the Inventory
        --------------------------
shall be determined as follows:

          a) The value of the Inventory as of the Closing shall be determined
from the books and records of the Seller. A physical inventory shall be taken on
December 29, 2001 and the books and records of the Seller shall be adjusted to
reflect the actual Inventory quantities as of such date (the "Physical Inventory
Amount"). The Physical Inventory Amount shall be valued in accordance with
paragraph (c) of this Section 6. Seller's representatives at Seller's expense
shall conduct such physical inventory jointly with Buyer' s representatives at
Buyer's expense.

          b) The Physical Inventory Amount shall be adjusted at close of
business on the date of the Closing to reflect any incoming receipts or outgoing
shipments that occurred between

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the physical inventory and close of business on the date of Closing (the "Final
Inventory Amount"). The books and records of the Seller shall be adjusted to
reflect the Final Inventory Amount. The Final Inventory Amount shall be valued
in accordance with paragraph (c) of this Section 6. The Final Inventory Amount
will be reflected on a "Final Inventory Statement".

          c) The Physical Inventory Amount and Final Inventory Amount reflected
on the Final Inventory Statement shall be determined in accordance with
generally accepted accounting principles, as applied by Seller ("GAAP").

          d) Any disagreement regarding the quantity or value of the Inventory,
or both, shall be resolved in the manner and at the time described in Section 7
(b) hereof.

     7. Post Closing Adjustment.
        -----------------------

          a) The Purchase Price will be adjusted dollar for dollar following the
Closing to the extent that the Final Inventory Amount shown upon the Final
Inventory Statement differs from $150,000 (the "Reference Amount"). Buyer and
Seller will jointly prepare the Final Inventory Statement in the manner set
forth in Section 6 above.

          b) If Buyer and Seller are unable to agree on the Final Inventory
Statement within thirty (30) days after the Closing, then any dispute regarding
the Final Inventory Statement will be resolved by an accounting firm mutually
acceptable to both parties or, in the absence of agreement, by an accounting
firm of national reputation selected by lot after eliminating Seller's and
Buyer's principal outside accountants. The determination by the accounting firm
so selected of the Final Inventory Statement and the Final Inventory Amount
shall be conclusive and binding upon the parties. The fees and expenses of such
accounting firm in acting under this Section 7 (b) shall be shared equally by
Buyer and Seller.

          c) If the Reference Amount is greater than the Final Inventory Amount,
then Seller shall pay to Buyer an amount equal to the difference. If the
Reference Amount is less than the Final Inventory Amount, then Buyer shall pay
to Seller an amount equal to the difference. Payment shall be made by the party
obligated to make such payment not more than five (5) business days following
the determination of the Final Inventory Amount pursuant to Section 7 (a)
hereof. Such payment shall bear interest from the date of Closing to the date of
payment at an interest rate equal to six percent (6%) per annum.

     8. Closing.
        -------

          a) The Closing shall take place at the offices of Seller or its
counsel on December 31, 2001, or in any other manner or any other place as the
parties may hereafter agree (the "Closing").

          b) If the Closing does not occur on or before December 31, 2001, this
Agreement shall terminate and be of no force and effect and neither Buyer nor
Seller shall have any obligation hereunder, except as otherwise specifically set
forth herein.

     9. Collections. Buyer will exercise its best efforts in assisting Seller in
        -----------
the collection and settling of the Seller's accounts receivable (the
"Accounts"). In the event that Buyer

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receives any payments on the Accounts, Buyer agrees to hold said payments in
trust for Seller and to forward said payments to Seller within ten (10) days of
receipt thereof.

     10. Buyer's Handling of Unfilled Orders. At the Closing, there shall exist
         -----------------------------------
certain purchase orders received by Seller prior to Closing which have not been
filled (the "Unfilled Orders"). A list of the Unfilled Orders is attached hereto
as Exhibit 4.

          a) Within sixty (60) days of Closing, Buyer shall fulfill, bill and
ship all products which were required to be provided by Seller under Unfilled
Orders.

          b) When fulfilling the Unfilled Orders, Buyer shall provide the
customers with Buyer's billing information for the remittance of payments due
thereon.

          c) Buyer shall hold in trust for Seller all payments received on the
Unfilled Orders and forward said payments less the cost of fulfilling the
Unfilled Orders to Seller within ten (10) days of receipt thereof. Buyer shall
prepare and delivery to Seller with said payments a statement detailing the
fulfillment costs associated with each Unfilled Order. Seller shall be
responsible for any commissions owned with respect to the Unfilled Orders.

          d) For the purposes of this Section, the term "Unfilled Orders" shall
apply only to those purchase orders received by Seller on or before the Closing,
but not yet filled as of the Closing or, if partially filled, then only to the
extent not yet filled as of the Closing.

     11. Earn-Out. The parties shall adjust the Purchase Price of the Assets
         --------
based on the gross revenue ("Gross Revenue"), as determined by GAAP, for the
calendar year 2002, of the Buyer's operation of the Business (the "Earn-Out")
under the following terms and conditions:

          a) Payment Calculation. For each dollar of Gross Revenue of the
             -------------------
Business for the calendar year 2002 in excess of One Million Three Hundred and
Fifty Thousand Dollars ($1,350,000) (the "Baseline"), Seller shall receive 10%
of each such dollar.

          By way of an example only, if the Gross Revenue in 2002 is $2,000,000,
the Seller would receive an Earn-Out payment of $65,000 (($2,000,000-$1,350,000)
* 10%)).

          b)   Determination of Gross Revenue.
               ------------------------------

               (i) Buyer will prepare and deliver financial statements,
          including a statement of operations of the Business (the "Income
          Statement") for year ended December 31, 2002 by February 28, 2003. The
          Income Statement shall be prepared in accordance with GAAP and will
          contain a calculation of Gross Revenue for such period. Buyer will
          give Seller's representatives access to its books and records and to
          the appropriate personnel of Buyer for purposes of confirming the
          Income Statement and the calculation of Gross Revenue. Unless Seller
          notifies Buyer, in writing, that it disagrees with the Income
          Statement and the calculation of Gross Revenue within thirty (30) days
          after receipt thereof, the Income Statement and the calculation of
          Gross Revenue shall be conclusive and binding on Buyer and Seller.

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               (ii) If Seller disagrees with Buyer's calculation of Gross
          Revenue for the Business for the year ended December 31, 2002 and
          notifies Buyer in writing of its disagreement with said calculation
          within thirty (30) days of its receipt of the Income Statement and
          calculation of Gross Revenue, then Buyer and Seller shall attempt to
          resolve their differences with respect thereto within thirty (30) days
          after Buyer's receipt of Seller's written notice of disagreement. Any
          dispute regarding the Income Statement not resolved by Buyer and
          Seller within such 30-day period will be resolved by an accounting
          firm mutually acceptable to both parties or, in the absence of
          agreement, by an accounting firm of national reputation selected by
          lot after eliminating Seller's and Buyer's principal outside
          accountants. The determination by the accounting firm so selected of
          such Gross Revenue shall be conclusive and binding upon the parties.
          Buyer and Seller shall share the fees and expenses of such accounting
          firm in acting under this Section 11(b) equally.

          c) Payment Terms. If the Buyer is obligated to make a payment pursuant
             -------------
to this Section 11, to the Seller, Buyer shall execute a promissory note
substantially similar to the note contained in Exhibit 5 attached hereto and
made a part hereof and make payments according to the terms thereof.

     12. Representations and Warranties of Seller. Seller hereby represents and
         ----------------------------------------
warrants as follows:

          a) Corporate.
             ---------

               (i) Seller is a corporation duly organized, validly existing and
          in good standing under the laws of Delaware and has all corporate
          power and authority to own or lease its properties and to carry on the
          Business as presently conducted.

               (ii) Seller has the requisite power to own the Assets and the
          right and power to sell, assign, transfer, convey and deliver the
          Assets to Buyer. All consents, approvals, authorizations and orders
          (corporate, governmental or otherwise) necessary for the due
          authorization, execution and delivery by Seller of this Agreement and
          the valid delivery of the Assets have been obtained or will be
          obtained prior to the Closing.

               (iii) This Agreement and the other documents delivered at the
          Closing have been duly executed and delivered and are the lawful,
          valid and legally binding obligations of Seller enforceable in
          accordance with their respective terms, except as enforcement may be
          limited by applicable bankruptcy, insolvency, rearrangement,
          reorganization or similar debtor relief legislation affecting the
          rights of creditors generally and subject to the application of
          general principles of equity. The execution and delivery of this
          Agreement will not result in a default under or a breach of (i) the
          charter or bylaws of Seller, (ii) any contract, agreement or other
          instrument to which the Seller or the Business are a party, (iii) any
          regulation, order, writ, decree or judgment of any court or
          governmental agency, or (iv) any law applicable to Seller or the
          Business and will

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          not restrict the ability of Buyer to use or dispose of the Assets.
          Seller has obtained each consent or approval by notice from any third
          party required on the part of Seller in connection with the execution
          and delivery by Seller of this Agreement or the consummation by Seller
          of the transaction contemplated hereby.

          b) Title to Assets. Except as set forth on Exhibit 6 attached hereto
             ---------------
and made a part hereof, Seller has good title to the Assets, free and clear of
any lien, pledge, charge, security interest, encumbrance, option, restriction or
other adverse claim thereto. The Assets are being sold to Buyer AS IS, WHERE IS,
WITH ALL FAULTS AND WITH NO REPRESENTATION AS TO MERCHANTABILITY, SALEABILITY OR
QUALITY.

          c) Litigation. There are no actions, suits, proceedings, arbitrations,
             -------------
or investigations pending, or to Seller's best knowledge, threatened, which
question the validity of this Agreement or any actions taken or to be taken in
connection herewith or the consummation of the transactions contemplated herein.

          d) Brokers/ Finders Fee. Seller has not retained any broker or finder
             --------------------
in connection with the transactions contemplated herein and is not obligated and
has not agreed to pay any brokerage or finder's commission, fee or similar
compensation.

     13. Representations and Warranties of Buyer. Buyer hereby represents and
         ---------------------------------------
warrants as follows:

          a) Corporate.
             ---------

               (i) Buyer is a corporation duly organized, validly existing and
          in good standing under the laws of Virginia and has all necessary
          power and authority to execute and deliver this Agreement, to carry on
          the businesses in which it is engaged, to own and use the properties
          owned and used by it, to consummate the transactions contemplated
          hereby, and perform its obligations hereunder.

               (ii) All corporate and other proceedings required to be taken on
          the part of Buyer, including, without limitation, all action required
          to be taken by the directors or shareholders of Buyer to authorize
          Buyer to enter into and carry out this Agreement and to purchase the
          Assets, have been, or prior to the Closing will be, duly and properly
          taken. This Agreement has been duly executed and delivered by Buyer
          and is the valid and binding obligation of Buyer enforceable against
          it in accordance with its terms, except as enforcement may be limited
          by equitable principles limiting the right to obtain specific
          performance or other equitable remedies, or by applicable bankruptcy
          or insolvency laws and related decisions affecting creditors' rights
          generally.

          b) Litigation. There are no actions, suits, proceedings, arbitrations,
             ----------
or investigations pending, or to Buyer's best knowledge, threatened, which
question the validity of this Agreement or any actions taken or to be taken in
connection herewith or the consummation of the transactions contemplated herein.

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          c) Brokers/Finders Fee. Buyer has not agreed or become obligated to
             -------------------
pay, and has not taken any action that might result in any person or entity
claiming to be entitled to receive, any brokerage commission, finder's fee or
similar commission or fee in connection with any of the transactions
contemplated hereby.

          d) No Consent. No consent, approval, authorization order, filing,
             ----------
registration or qualification of or with any court, governmental authority or
third person is required to be made or obtained by Buyer in connection with the
execution and delivery of this Agreement by Buyer or the consummation by Buyer
of the transactions contemplated hereby.

          e) No Interference. Buyer agrees not to undertake, directly or
             ---------------
indirectly, any action that will materially adversely affect or interfere with
Seller's rights in and obligations to its Accounts and Liabilities.

     14. Seller's Conditions to Close. Each and every obligation of Seller under
         ----------------------------
this Agreement is subject to the satisfaction of the following conditions:

          a) Each of the representations and warranties of Buyer contained
herein shall be true and correct in all material respects as of the Closing.

          b) Buyer shall have performed, satisfied and complied with all
covenants, agreements and conditions required by this Agreement to be performed,
satisfied and complied with by it as of the Closing.

          c) No action, suit or proceeding before any court or governmental body
pertaining to the Assets or to the transactions contemplated by this Agreement
shall have been instituted or threatened as of the Closing.

          d) Buyer shall deliver to Seller a true and correct copy of the
resolutions of the Buyer's Board of Directors authorizing the execution and
delivery of this Agreement and the consummation of the transactions contemplated
thereby, certified by a duly elected, qualified and acting officer of the Buyer
in form and substance satisfactory to the Seller.

          e) Buyer shall execute a security agreement in the form attached
hereto as Exhibit 7 securing the Note.

          f) Buyer shall execute a promissory note in original principal sum of
$375,000 for the cash portion of the purchase price (the "$375,000 Note") in the
form attached hereto as Exhibit 8.

          g) Buyer shall execute a Revolving Promissory Note (the "Revolving
Note") in the form attached hereto as Exhibit 9 and Anthony Fanale shall execute
a Guaranty of such note in the form attached hereto as Exhibit 10.

          h) Buyer shall execute a security agreement in the form attached
hereto as Exhibit 11 securing the Revolving Note and the $375,000 Note.

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     15. Buyer's Conditions to Close. Each and every obligation of Buyer under
         ---------------------------
this Agreement is subject to the satisfaction of the following conditions:

          a) Each of the representations and warranties of Seller contained
herein shall be true and correct in all material respects as of the Closing.

          b) Seller shall have performed, satisfied and complied with all
covenants, agreements and conditions required by this Agreement to be performed,
satisfied and complied with by it as of the Closing.

          c) No action, suit or proceeding before any court or governmental body
pertaining to the Assets or to the transactions contemplated by this Agreement
shall have been instituted or threatened as of the Closing.

     16. Covenant of Seller. Seller shall perform any and all actions and shall
         ------------------
execute any and all documents necessary to accomplish the transfer of the
Assets, as reasonably requested by Buyer.

     17. Covenant of Buyer. Buyer shall perform any and all actions and shall
         -----------------
execute any and all documents necessary to accomplish the transfer of the
Assets, as reasonably requested by Seller.

     18. Covenant Not To Compete.
         -----------------------

          a) Seller agrees that for a period of Thirty (30) months immediately
following the Closing, neither Seller nor any of its related or affiliated
entities will directly or indirectly, operate, perform, have any interest in or
otherwise be engaged in or concerned with any business which manufactures
nonwoven fabric filter products for use in high temperature pulse-jet baghouses.
For these purposes, ownership of securities of a company whose securities are
publicly traded under a recognized securities exchange not in excess of 5% of
any class of such securities shall not be considered to be competition with
Buyer.

          b) Further, Seller agrees that for Thirty (30) months following the
Closing, neither Seller nor any of its related or affiliated entities will
induce any of Buyer's employees to terminate his or her relationship with Buyer
to work for Seller.

          c) Each of Seller and Buyer acknowledges that the restrictions on its
activities under this Section 18 are necessary for the reasonable protection of
Buyer and constitute a material inducement to Buyer's entering into and
performing this Agreement.

     19. Indemnification.
         ---------------

          a) Indemnification by Seller. Seller agrees to indemnify, defend,
             -------------------------
protect and hold harmless Buyer from, against and in respect of all liabilities,
losses, claims, damages, causes of action, lawsuits, demands, assessments and
costs and expenses (including reasonable attorney's fees and disbursements of
every kind, nature and description) suffered, sustained, incurred or paid by
Buyer in connection with, resulting from or arising out of, directly or
indirectly, any breach of any representation or warranty of Seller set forth in
this Agreement, or

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any agreement executed in connection herewith; or any nonfulfillment of any
covenant or agreement on the part of Seller in this Agreement.

          b) Indemnification by Buyer. Buyer agrees to indemnify, defend,
             ------------------------
protect and hold harmless Seller from, against and in respect of all
liabilities, losses, claims, damages, causes of action, lawsuits, demands,
assessments and costs and expenses (including reasonable attorney's fees and
disbursements of every kind, nature and description) suffered, sustained,
incurred or paid by Seller in connection with, resulting from or arising out of,
directly or indirectly, any breach of any representation or warranty of Buyer
set forth in this Agreement, or any agreement executed in connection herewith;
or any nonfulfillment of any covenant or agreement on the part of Buyer in this
Agreement.

          c) Defense of Actions. Each party indemnified pursuant to Sections
             ------------------
19(a) or 19(b) hereof (an "Indemnified Party") will give the indemnitor (the
"Indemnitor") written notice of any action or proceeding relating to a claim or
loss for which indemnity is sought hereunder within ten (10) business days after
any such Indemnified Party shall have had actual notice thereof; provided,
however, that failure to give such notice shall not impair the Indemnified
Party's rights unless the Indemnitor is actually prejudiced by such failure. The
Indemnified Party and the Indemnitor shall work cooperatively to minimize any
claim or loss for which indemnity is sought and the Indemnitor shall have ten
(10) days after receipt of the aforementioned written notice to cure any breach
(to the extent that such breach can be cured) that leads to a request for
indemnity. The Indemnitor, at its option and expense, shall be entitled to
participate in or direct the defense or settlement of such action, provided the
Indemnitor employs counsel reasonably satisfactory to such Indemnified Party;
provided that prior to the Indemnitor assuming control of such defense it shall
first demonstrate to the Indemnified Party in writing such Indemnitor's
financial ability to provide full indemnification to the Indemnified Party with
respect to such action, lawsuit, proceeding, investigation or other claim giving
rise to such claim for indemnification hereunder and provided further, that:

               (i) the Indemnified Party shall be entitled to participate in the
          defense of such claim and to employ counsel of its choice for such
          purpose; provided that the fees and expenses of such separate counsel
          shall be borne by the Indemnified Party other than any fees and
          expenses of such separate counsel that are reasonably incurred prior
          to the date Indemnitor effectively assumes control of such defense
          which, notwithstanding the foregoing shall be borne by the Indemnitor,
          provided, however, that the Indemnified Party is not responsible for
          any delay in Indemnitor assuming control of such defense.

               (ii) if the Indemnitor shall control the defense of any such
          claim, the Indemnitor shall obtain the prior written consent of the
          Indemnified Party before entering into any settlement of a claim or
          ceasing to defend such claim if, pursuant to or as a result of such
          settlement or cessation, injunctive or other equitable relief will be
          imposed against the Indemnitee or if such settlement does not
          expressly and unconditionally release the Indemnified Party from all
          liabilities and obligations with respect to such claim, without
          prejudice.

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          Such Indemnified Party shall have the right to employ its own counsel
          in any such case, but the Indemnitor shall not have the right to
          assume control of such defense and the fees and expenses of such
          counsel shall be borne by such Indemnified Party in the event (i) the
          employment of such counsel has been authorized by the Indemnitor, (ii)
          the Indemnitor fails to defend the claim in a vigorous and time
          manner, or (iii) such Indemnified Party and counsel selected by the
          Indemnitor shall reasonably conclude that there are defenses available
          to the Indemnified Party that are in conflict with those available to
          the Indemnitor. In the event of any of (i), (ii) or (iii), expenses of
          counsel employed by such Indemnified Party shall be borne by the
          Indemnitor.

          d) Limitations on Indemnification. No Indemnitor shall be liable to an
             ------------------------------
Indemnified Party with respect to violations of the representations and
warranties pursuant to Section 19(a) or 19(b) hereof until the total of all
claims or losses for breaches of representations and warranties for which
indemnity is sought by such Indemnified Party exceeds $50,000 and then only for
the amount by which such claims and losses exceed $50,000. In no event shall the
maximum aggregate liability of the Seller or Buyer pursuant to Section 19(a)
hereof exceed $150,000. For purposes of determining whether there has been a
breach of a representation or warranty, the representations and warranties set
forth in this Agreement shall be considered without regard to any materiality
qualification set forth therein.

          e) Other Remedies. The right of an Indemnified Party to be indemnified
             --------------
under this Section 19 shall not limit, reduce or otherwise affect, except as
expressly provided herein, the rights and remedies of such Indemnified Party
with respect to the matters indemnified hereunder. Any indemnification of the
Buyer or the Seller pursuant to this Section 19 shall be effected by wire
transfer of immediately available funds to an account designated by the Buyer or
the Seller, as the case may be, within fifteen (15) days following the
determination thereof.

     20. Post Closing Covenants. From and after the date of this Agreement, the
         ----------------------
parties covenant, represent and warrant as follows:

          a) Continued Assistance. Seller shall refer to Buyer, as promptly as
             --------------------
practicable, any telephone calls, letters, orders, notices, requests, inquiries
and other communications relating to the Business or the Assets.

          b) Certain Payments. Following the Closing, Seller shall use
             ----------------
reasonable efforts to pay and fully discharge all Liabilities within ninety (90)
days of Closing.

          c) Access to Records. Following the Closing, Seller and Buyer shall
             -----------------
allow each other access to available books and records of Seller's Business as
either shall reasonably request.

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     21. Remedies.
         --------

          a) The rights and remedies provided by this Agreement and at law or
equity are cumulative and the use of any one right or remedy by any party does
not preclude or waive the right to use any or all other remedies. Such rights
and remedies are given in addition to any other rights the parties may have by
law, statute or otherwise.

     22. Notice. Any notice or demand to be given hereunder by either party
         ------
shall be effected by personal delivery in writing or by certified mail, postage
prepaid, return receipt requested, and shall be deemed communicated forty-eight
(48) hours after mailing. Mailed notices shall be addressed to the parties as
follows:

                If to Buyer:       Belfiber, Co.
                                   115 Oakley Street
                                   PO Box 597
                                   South Hill, VA 23970
                                   Attn: Anthony Fanale

                If to Seller:      Air Purator Corporation
                                   15 Fifth Street, Area B
                                   Taunton, Massachusetts 02780

                With a Copy to:    Marshall Morris
                                   Vice President of Finance and Administration/
                                   Chief Financial Officer
                                   CECO Environmental Corporation
                                   3120 Forrer Street
                                   Cincinnati, Ohio 45209

or such other address as the parties may indicate by written notice.

     23. Arbitration. Any controversy, dispute or claim arising out of, in
         -----------
connection with, or in relation to the interpretation, performance or breach of
this Agreement, or any amount due hereunder, including, without limitation, any
claim based on contract, tort or statute shall be settled, solely and
exclusively, by arbitration. Any arbitration pursuant to this Agreement shall be
conducted in Cincinnati, Ohio before and in accordance with the then existing
Commercial Dispute Resolution Procedures through the American Arbitration
Association, using an arbitrator mutually selected by Buyer, and Seller, or
applicable from a list of those designated by the American Arbitration
Association. Any arbitration shall be final and binding. The findings shall be
delivered in a written opinion with findings of fact based on the record. Any
judgment upon any interim or final award or order rendered by the arbitrator may
be entered by any State or Federal court having jurisdiction thereof. The
parties intend that any agreement pursuant hereto to arbitrate be valid,
enforceable and irrevocable. Each party in any arbitration proceeding commenced
hereunder shall bear such party's own costs and expenses (including expert
witness and attorneys' fees) of investigating, preparing and pursuing such
arbitration claim.

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     24.  Miscellaneous.
          -------------

          a) All representations and warranties contained herein or made in
writing by or on behalf of any party to this Agreement in connection with this
Agreement and the provisions of Sections 12, 13, 14, 15, 16, 17,18, 19, 20 and
23 shall survive the Closing of this transaction.

          b) This Agreement shall be binding upon and inure to the benefit of
the parties and their respective successors and assigns. No party may assign any
of its rights or obligations hereunder without the prior written consent of the
other party.

          c) This Agreement constitutes the entire Agreement between the parties
with respect to the subject matter hereof and supersedes all previous
negotiations, commitments and writings.

          d) If any provision of this Agreement shall be held unenforceable,
invalid or void to any extent for any reason, such provision shall remain in
force and effect to the maximum extent allowable, if any, and the enforceability
or validity of the remaining provisions of this Agreement shall not be affected
thereby.

          e) This Agreement may only be amended, modified, superceded or
supplemented by a written instrument duly executed by both parties hereto.

          f) The failure of any party to enforce any provision of this Agreement
shall not be a waiver of any other provision or subsequent breach of the same or
any other obligation hereunder.

          g) This Agreement may be executed in counterparts each of which will
deemed an original but all of which will constitute one and the same instrument.
Facsimile signatures shall have the same force and effect as original
signatures.

          h) The paragraph headings of this Agreement are for reference only and
shall not be considered in the interpretation of this Agreement.

          i) This Agreement shall be construed in accordance with and governed
by the law of the State of Ohio.

     IN WITNESS WHEREOF, the parties have executed this Agreement.

AIR PURATOR CORPORATION,                 BELFIBER, CO.,
a Delaware corporation                       a Virginia corporation

By /s/ Michael J. Meyer                     By /s/ Anthony Fanale
  -----------------------------                ---------------------------------
Name                                         Name  Anthony Fanale
    ---------------------------                  -------------------------------
Its    President                             Its
   ----------------------------                 --------------------------------

                                    12<PAGE>

                                                                   Exhibit 10.48

     THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
     1933, AS AMENDED, OR ANY STATE SECURITIES LAWS. THEY HAVE BEEN
     ACQUIRED SOLELY FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN
     CONNECTION WITH, THE SALE OR DISTRIBUTION THEREOF. THEY MAY NOT BE
     SOLD, OFFERED FOR SALE, PLEDGED, HYPOTHECATED OR OTHERWISE DISTRIBUTED
     IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO
     OR AN OPINION OF COUNSEL, SATISFACTORY IN FORM AND SUBSTANCE TO THE
     COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED UNDER THE SECURITIES
     ACT OF 1933, AS AMENDED AND ANY APPLICABLE STATE SECURITIES LAWS.

                                     WARRANT

                                                               December 31, 2001

                  To Purchase        Shares of Common Stock of
                              ------
        CECO Environmental Corp., a New York corporation (the "Company")

     1. Number of Shares; Exercise Price; Term. This certifies that for good and
        --------------------------------------
valuable consideration, receipt and sufficiency of which are hereby acknowledged
               ("Holder") is entitled, upon the terms and subject to the
--------------
conditions hereinafter set forth, at any time after December 31, 2001, and at or
prior to 11:59 p.m. Central Time, on December 31, 2006 (the "Expiration Time"),
but not thereafter, to acquire from the Company, in whole or in part, from time
to time, up to                     (       ) fully paid and nonassessable shares
               -------------------  -------
(the "Shares") of common stock, $0.011 par value, of the Company ("Common
Stock"), at a purchase price of $3.60 per share (the "Exercise Price"). The
right to purchase all of the Shares under the Warrant shall vest immediately
upon issuance of this Warrant. The number of Shares, type of security and
Exercise Price are subject to adjustment as provided herein, and all references
to "Common Stock" and "Exercise Price" herein shall be deemed to include any
such adjustment or series of adjustments.

     2. Exercise of Warrant. The purchase rights represented by this Warrant are
        -------------------
exercisable by the Holder, in whole or in part, at any time, or from time to
time, prior to the Expiration Time and the Notice of Exercise annexed hereto,
all duly completed and executed on behalf of the Holder, at the office of the
Company in Toronto, Ontario (or such other office or agency of the Company as it
may designate by notice in writing to the Holder at the address of the Holder
appearing on the books of the Company) and upon payment of the Exercise Price
for the Shares thereby purchased (i) by cash, certified or cashier's check, or
wire transfer payable to the Company or (ii) cashless exercise, in which case a
Holder shall indicate on the Notice of Exercise that the Holder is exercising
this Warrant or a portion thereof by authorizing the Company to withhold from
issuance that number of shares of the Common Stock issuable upon such exercise
of the Warrant which when multiplied by the Market Price (as defined below) of
the Common Stock is equal to the aggregate Exercise Price of this Warrant or the
portion being

                                       1

<PAGE>

exercised.). Thereupon, the Holder as the holder of this Warrant, shall be
entitled to receive from the Company a stock certificate in proper form
representing the number of Shares so purchased, and a new Warrant in
substantially identical form and dated as of such exercise for the purchase of
that number of Shares equal to the difference, if any, between the number of
Shares subject hereto and the number of Shares as to which this Warrant is so
exercised.

     3. Issuance of Shares. Certificates for Shares purchased hereunder shall be
        ------------------
delivered to the Holder within a reasonable time after the date on which this
Warrant shall have been exercised in accordance with the terms hereof. All
Shares that may be issued upon the exercise of this Warrant shall, upon such
exercise, be duly and validly authorized and issued, fully paid and
nonassessable and free from all taxes, liens and charges in respect of the
issuance thereof (other than liens or charges created by or imposed upon the
Holder as the holder of the Warrant or taxes in respect of any transfer
occurring contemporaneously or otherwise specified herein). The Company agrees
that the Shares so issued shall be and shall for all purposes be deemed to have
been issued to the Holder as the record owner of such Shares as of the close of
business on the date on which this Warrant shall have been exercised or
converted in accordance with the terms hereof. The Company will at all times
reserve and keep available, solely for issuance, sale and delivery upon the
exercise of this Warrant, such number of Shares, equal to the number of such
Shares purchasable upon the exercise of this Warrant.

     4. No Fractional Shares or Scrip. No fractional Shares or scrip
        -----------------------------
representing fractional Shares shall be issued upon the exercise of this
Warrant. In lieu of any fractional Warrant Share to which the Holder as the
holder would otherwise be entitled, the Holder shall be entitled, at its option,
to receive either (i) a cash payment equal to the excess of Market Value for
such fractional Warrant Share above the Exercise Price for such fractional share
(as determined in good faith by the Company) or (ii) a whole Warrant Share if
the Holder tenders the Exercise Price for one whole share.

     5. No Rights as Shareholders. This Warrant does not entitle the Holder as a
        -------------------------
holder hereof to any voting rights or other rights as a shareholder of the
Company prior to the exercise hereof.

     6. Exchange and Registry of Warrant. This Warrant is exchangeable, upon the
        --------------------------------
surrender hereof by Holder as the registered holder at the above-mentioned
office or agency of the Company, for a new Warrant of substantially identical
form and dated as of such exchange. The Company shall maintain at the
above-mentioned office or agency a registry showing the name and address of
Holder as the registered Holder of this Warrant. This Warrant may be surrendered
for exchange or exercise, in accordance with its terms, at the office of the
Company, and the Company shall be entitled to rely in all respects, prior to
written notice to the contrary, upon such registry.

     7. Loss, Theft, Destruction or Mutilation of Warrant. Upon receipt by the
        -------------------------------------------------
Company of evidence reasonably satisfactory to it of the loss, theft,
destruction or mutilation of this Warrant, and in the case of loss, theft or
destruction, of indemnity or security reasonably satisfactory to it, and upon
reimbursement to the Company of all reasonable expenses incidental thereto, and
upon surrender and cancellation of this Warrant, if mutilated, the Company will

                                       2

<PAGE>

make and deliver a new Warrant of like tenor and dated as of such cancellation
and reissuance, in lieu of this Warrant.

     8. Saturdays, Sundays, Holidays, etc. If the last or appointed day for the
        ----------------------------------
taking of any action or the expiration of any right required or granted herein
shall be a Saturday or a Sunday or shall be a legal holiday, then such action
may be taken or such right may be exercised on the next succeeding day not a
Saturday or a Sunday or a legal holiday.

     9. Adjustments of Rights. The purchase price per Share and/or the number of
        ---------------------
Shares purchasable hereunder are subject to adjustment from time to time as
follows:

          (a) Merger or Consolidation. If at any time there shall be a merger or
              -----------------------

a consolidation of the Company with or into another corporation when the Company
is not the surviving corporation, then, as part of such merger or consolidation,
lawful provision shall be made so that the Holder as the holder of this Warrant
shall thereafter be entitled to receive upon exercise of this Warrant, during
the period specified herein and upon payment of the aggregate Exercise Price
then in effect, the number of shares of stock or other securities or property
(including cash) of the successor corporation resulting from such merger or
consolidation, to which the Holder as the holder of the stock deliverable upon
exercise of this Warrant would have been entitled in such merger or
consolidation if this Warrant had been exercised immediately before such merger
or consolidation. In any such case, appropriate adjustment shall be made in the
application of the provisions of this Warrant with respect to the rights and
interests of the Holder as the holder of this Warrant after the merger or
consolidation. This provision shall apply to successive mergers or
consolidations.

          (b) Reclassification, Recapitalization, etc. If the Company at any
              ---------------------------------------
time shall, by subdivision, combination or reclassification of securities,
recapitalization, automatic conversion, or other similar event affecting the
number or character of outstanding shares of Common Stock, or otherwise, change
any of the securities as to which purchase rights under this Warrant exist into
the same or a different number of securities of any other class or classes, this
Warrant shall thereafter represent the right to acquire such number and kind of
securities as would have been issuable as the result of such change with respect
to the securities that were subject to the purchase rights under this Warrant
immediately prior to such subdivision, combination, reclassification or other
change.

          (c) Split, Subdivision or Combination of Shares. If the Company at any
              -------------------------------------------
time while this Warrant remains outstanding and unexpired shall split, subdivide
or combine the securities as to which purchase rights under this Warrant exist,
the Exercise Price shall be proportionately decreased in the case of a split or
subdivision or proportionately increased in the case of a combination.

          (d) Common Stock Dividends. If the Company at any time while this
              ----------------------
Warrant is outstanding and unexpired shall pay a dividend with respect to Common
Stock payable in shares of Common Stock, or make any other distribution with
respect to Common Stock payable in shares of Common Stock, then the Exercise
Price shall be adjusted, from and after the date of determination of the
shareholders entitled to receive such dividend or distribution, to that price
determined by multiplying the Exercise Price in effect immediately

                                       3

<PAGE>

prior to such date of determination by a fraction (i) the numerator of which
shall be the total number of shares of Common Stock outstanding immediately
prior to such dividend or distribution, and (ii) the denominator of which shall
be the total number of shares of Common Stock outstanding immediately prior to
such dividend or distribution, plus the number of shares of common stock
issuable in payment of such dividend or distribution.

     10. Adjustment of Number of Shares. Upon each adjustment in the Exercise
         ------------------------------
Price pursuant to Section 9 hereof, the number of Shares purchasable hereunder
shall be adjusted, to the nearest whole Share, to the product obtained by
multiplying the number of Shares purchasable immediately prior to such
adjustment by a fraction (i) the numerator of which shall be the Exercise Price
immediately prior to such adjustment, and (ii) the denominator of which shall be
the Exercise Price immediately after such adjustment.

     11. Notice of Adjustments; Notices. Whenever the Exercise Price or number
         ------------------------------
or type of securities issuable hereunder shall be adjusted pursuant to Sections
9 and 10 hereof, the Company shall issue and provide to the Holder as the holder
of this Warrant, within fifteen (15) business days after the event requiring the
adjustment, a certificate signed by an officer of the Company setting forth, in
reasonable detail, the event requiring the adjustment, the amount of the
adjustment, the method by which such adjustment was calculated and the Exercise
Price and number of Shares purchasable hereunder after giving effect to such
adjustment.

     12. Governing Law. This Warrant shall be binding upon any successors or
         -------------
assigns of the Company. This Warrant shall constitute a contract under the laws
of New York and for all purposes shall be construed in accordance with and
governed by the laws of said state, without giving effect to the conflict of
laws principles.

     13. Amendments. This Warrant may be amended and the observance of any term
         ----------
of this Warrant may be waived only with the written consent of the Company and
the Holder as the holder hereof.

     14. Notice. All notices hereunder shall be in writing and shall be
         ------
effective (a) on the day on which delivered if delivered personally or
transmitted by telecopier with evidence of receipt, (b) one business day after
the date on which the same is delivered to a nationally recognized overnight
courier service with evidence of receipt, or (c) five business days after the
date on which the same is deposited, postage prepaid, in the U.S. mail, sent by
certified or registered mail, return receipt requested, and addressed to the
party to be notified at the address indicated below for the Company, or at the
address for the Holder set forth in the registry maintained by the Company
pursuant to Section 6 (which initially shall be as set forth in the last page of
this Warrant), or at such other address and/or telecopy and/or to the attention
of such other person as the Company or the Holder may designate by ten-day
advance written notice. Any notice to the Company shall include a copy sent in
the same manner as notices are sent hereunder to Leslie J. Weiss, Sugar,
Friedberg & Felsenthal, 30 N. LaSalle, Suite 2600, Chicago, IL 60602.

                                       4

<PAGE>

     15. Registration Rights
         -------------------

          (a) Piggyback Registration. If, at any time commencing January 1,
              ----------------------
2002, and expiring on the Expiration Time, the Company proposes to register any
of its securities, not registered on the date hereof, under the Securities Act
of 1933 (the "Act") (other than in connection with a merger or pursuant to Form
S-4 or Form S-8 or any similar form) it will give written notice by certified or
registered mail, at least twenty (20) days prior to the filing of each such
registration statement, to the Holders of this Warrant and/or the Shares of its
intention to do so. If any of the Holders of the Warrants and/or Shares notify
the Company within fifteen (15) days after mailing of any such notice of its or
their desire to include any such securities in such proposed registration
statement, the Company shall afford such Holders of the Warrants and/or Shares
the opportunity to have any such Shares registered under such registration
statement. In the event that the managing underwriter for said offering advises
the Company in writing that in the underwriter's opinion the number of
securities requested to be included in such registration exceeds the number
which can be sold in such offering without causing a diminution in the offering
price or otherwise adversely affecting the offering, the Company will include in
such registration (a) first, the securities the Company proposes to sell, (b)
second, the securities held by the persons that made a demand for registration,
(c) third, the Shares and other securities requested to be included in such
registration pursuant to piggyback registration rights which in the opinion of
such underwriter, and if there is no underwriter, the Board of Directors, in
good faith, can be sold, pro rata among such persons on the basis of the number
of Shares and other securities requested to be registered by such persons, and
(d) fourth, other securities requested to be included in such registration.

         Notwithstanding the provisions of this Section 15(a), the Company
shall have the right at any time after it shall have given written notice
pursuant to this Section 15(a) (irrespective of whether a written request
for inclusion of any such securities shall have been made) to elect not to
file any such proposed registration statement or to withdraw the same after
the filing but prior to the effective date thereof.

          (b) Covenants of the Company With Respect to Registration.
              -----------------------------------------------------

               In connection with any registration under Section 15(a) hereof,
the Company covenants and agrees as follows:

               (I) The Company shall furnish to the Holder with respect to the
Shares registered under the registration statement such number of copies of the
registration statement, prospectuses and preliminary prospectuses in conformity
with the requirements of the Act and such other documents as the Holder may
reasonably request, in order to facilitate the public sale or other disposition
of all or any of the Shares by the Holder, provided, however, that the
obligation of the Company to deliver copies of prospectuses or preliminary
prospectuses to the Holder shall be subject to the receipt by the Company of
reasonable assurances from the Holder that the Holder will comply with the
applicable provisions of the Act and of such other securities or blue sky laws
as may be applicable in connection with any use of such prospectuses or
preliminary prospectuses. The Company shall also file such applications and
other documents as may be necessary to permit the sale of the Shares to the
public during the registration period in those states to which the Company and
the holders of the Shares shall mutually agree.

                                       5

<PAGE>

               (II) The Company shall pay all costs (excluding fees and expenses
of Holder(s)' counsel and any underwriting or selling commissions), fees and
expenses in connection with all registration statements filed pursuant to
Section 15(a) hereof including, without limitation, the Company's legal and
accounting fees, printing expenses, blue sky fees and expenses.

               (III) The Company shall indemnify the Holder(s) of the Shares to
be sold pursuant to any registration statement and each person, if any, who
controls such Holder(s) within the meaning of Section 15 of the Act or Section
20(a) of the Securities Exchange Act of 1934, as amended ("Exchange Act"),
against all loss, claim, damage, expense or liability (including all expenses
reasonably incurred in investigating, preparing or defending against any claim
whatsoever) to which any of them may become subject under the Act, the Exchange
Act or otherwise, arising from such registration statement, except for losses,
claims, damages, expenses or liabilities resulting from, based on or arising out
of information included in the registration statement based on written
disclosure provided by the Holder(s) to the Company specifically for inclusion
in the registration statement.

               (IV) In order to provide for just and equitable contribution
under the Act in any case in which (i) any Holder of the Shares or controlling
person thereof makes a claim for indemnification but it is judicially determined
(by the entry of a final judgment or decree by a court of competent jurisdiction
and the expiration of time to appeal or the denial of the last right of appeal)
that such indemnification may not be enforced in such case notwithstanding the
fact that the express provisions of Section 15(b)(III) hereof provide for
indemnification in such case or (ii) contribution under the Act may be required
on the part of any Holder of the Shares, or controlling person thereof, then the
Company, any such Holder of the Shares, or controlling person thereof shall
contribute to the aggregate losses, claims, damages or liabilities to which they
may be subject (which shall, for all purposes of this Agreement, include, but
not be limited to, all costs of defense and investigation and all attorneys
fees), in either such case (after contribution from others) on the basis of
relative fault as well as any other relevant equitable considerations. The
relative fault shall be determined by reference to, among other things, whether
the untrue or alleged untrue statement of a material fact or the omission or
alleged omission to state a material fact relates to information supplied by the
Company on the one hand or a Holder of Shares, or controlling person thereof on
the other and the parties' relative intent, knowledge, access to information and
opportunity to correct or prevent such statement or omission. The Company and
such Holders of such securities and such controlling persons agree that it would
not be just and equitable if contribution pursuant to this Section 15(b)(IV)
were determined by pro rata allocation or by any other method which does not
take account of the equitable considerations referred to in this Section
15(b)(IV). The amount paid or payable by an indemnified party as a result of the
losses, claims, damages or liabilities (or actions in respect thereof) referred
to above in this Section 15(b)(IV) shall be deemed to include any legal or other
expenses reasonably incurred by such indemnified party in connection with
investigating or defending any such action or claim. No person guilty of
fraudulent misrepresentation (within the meaning of Section 11(f) of the Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation.

               (V) The Holder(s) of the Shares to be sold pursuant to a
registration statement, and their successors and assigns, shall severally, and
not jointly, indemnify the Company, its officers and directors and each person,
if any, who controls the Company within the meaning of Section 15 of the Act or
Section 20(a) of the Exchange Act, against any loss, claim, damage or

                                       6

<PAGE>

expense or liability (including all expenses reasonably incurred in
investigating, preparing or defending against any claim whatsoever) to which
they may become subject under the Act, the Exchange Act or otherwise, arising
from information furnished in writing, by or on behalf of such Holders, or their
successors or assigns, for specific inclusion in such registration statement.

               (VI) advise the Holder, promptly after it shall receive notice or
obtain knowledge of the issuance of any stop order by the SEC delaying or
suspending the effectiveness of the Registration Statement or of the initiation
or threat of any proceeding for that purpose; and it will promptly use its
reasonable efforts to prevent the issuance of any stop order or to obtain its
withdrawal at the earliest possible moment if such stop order should be issued.

               (VII) Nothing contained in this Agreement shall be construed as
requiring the Holder(s) to exercise their Warrants prior to the initial filing
of any registration statement or the effectiveness thereof.

     16. Obligations of Holders. It shall be a condition precedent to the
         ----------------------
obligations of the Company to take any action pursuant to Section 15 hereof that
each of the selling Holders shall:

          (a) Furnish to the Company such information regarding themselves, the
Shares held by them, the intended method of sale or other disposition of such
securities, the identity of and compensation to be paid to any underwriters or
dealers proposed to be employed in connection with such sale or other
disposition, and such other information as may reasonably be required to effect
the registration of their Shares.

          (b) The Holder agrees that it will promptly notify the Company of any
changes in the information set forth in the registration statement regarding the
Holder or its plan of distribution.

          (c) Notify the Company, at any time when a prospectus relating to the
Shares covered by a registration statement is required to be delivered under the
Act, of the happening of any event with respect to such selling Holder as a
result of which the prospectus included in such registration statement, as then
in effect, includes an untrue statement of a material fact or omits to state a
material fact required to be stated therein or necessary to make the statements
therein not misleading in the light of the circumstances then existing.

     17. Transfer. This Warrant may be transferred, in whole or in part, only
         --------
pursuant to an effective registration statement filed under the Act, or an
applicable exemption therefrom as provided in the transfer conditions referred
to in the legend endorsed on the first page of this Warrant.

     18. Entire Agreement. This Warrant and the form attached hereto contain the
         ----------------
entire agreement between the parties with respect to the subject matter hereof
and supersede all prior and contemporaneous arrangements or undertakings with
respect thereto.

     19. Market Price. "Market Price" means as to any security the closing price
         ------------
of such security's sales on the principal securities exchange on which such
security may at the time be listed, or, if there have been no sales on any such
exchange on any day, the average of the highest

                                       7

<PAGE>

bid and lowest asked prices on such exchange at the end of such day, or, if on
any day such security is not so listed, the average of the representative bid
and asked prices quoted in the NASDAQ System as of 4:00 P.M., New York time, on
such day, or, if on any day such security is not quoted in the NASDAQ System,
the average of the highest bid and lowest asked prices on such day in the
domestic over-the-counter market as reported by the National Quotation Bureau,
Incorporated, or any similar successor organization, in each such case averaged
over a period of 21 days consisting of the day as of which "Market Price" is
being determined and the 20 consecutive business days prior to such day. If at
any time such security is not listed on any securities exchange or quoted in the
NASDAQ System or the over-the-counter market, the "Market Price" shall be the
fair value thereof without discount for lack of marketability or minority
discount determined by the Board of Directors of the Company.

     IN WITNESS WHEREOF, CECO Environmental Corp. has caused this Warrant to be
executed by its duly authorized officer.

                                             Dated As Of: December 31, 2001
                                             CECO Environmental Corp.,
                                             a New York corporation

                                             By:
                                                      --------------------------
                                             Its:
                                                      --------------------------

Name, Address and
Social Security Number of Holder:

--------------------------------

--------------------------------

--------------------------------

--------------------------------

                                       8

<PAGE>

                               NOTICE OF EXERCISE
                               ------------------

To:  CECO Environmental Corp.

     1. The undersigned hereby elects to purchase                  shares (the
                                                  ----------------
"Shares") of common stock $0.01 par value of CECO Environmental Corp. (the
"Company") pursuant to the terms of the attached Warrant, and (check on of the
following):

          tenders herewith payment of the purchase price and any transfer taxes
     ----
payable pursuant to the terms of the Warrant, together with an investment
representation statement in form and substance satisfactory to legal counsel to
the Company; or

           gives direction to the Company to withhold from issuance a number of
     -----
Shares issuable upon exercise of the Warrant (or portion thereof) which when
multiplied by the Market Price (as defined in the Warrant) of the Shares is
equal to the aggregate exercise price of this Warrant (or portion being
exercised) and an investment representation statement in form and substance
satisfactory to legal counsel to the Company.

     2. The Shares to be received by the undersigned upon exercise of the
Warrant are being acquired for its own account, not as a nominee or agent, and
not with a view to resale or distribution of any part thereof, and the
undersigned has no present intention of selling, granting any participation in,
or otherwise distributing the same, except in compliance with applicable federal
and state securities laws. The undersigned further represents that it does not
have any contract, undertaking, agreement or arrangement with any person to
sell, transfer or grant participation to such person or to any third person,
with respect to the Shares. The undersigned believes it has received all the
information it considers necessary or appropriate for deciding whether to
purchase the Shares.

     3. Please issue a certificate or certificates representing said Shares in
the name of the undersigned.

     4. Please issue a new Warrant for the unexercised portion of the attached
Warrant in the name of the undersigned.

                                          a)
                                                   -----------------------------
                                                   Signature

                                          b)
                                                   -----------------------------
                                                   Date

                                       9

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