This order becomes a binding contract, subject to the terms and conditions thereof, upon the Seller signing the acknowledgment of the order and returning signed copy to the Buyer; the Seller notifies the Buyer that Seller intends to commence performance of the order; the Seller commences performance of the order. Any modification of this order, to be valid, must be in writing and signed by Buyer’s authorized purchasing representative. Any acknowledgment form or other form of Seller containing terms and conditions of sale submitted by Seller to Buyer shall not have the effect of modifying the terms and conditions hereof. Buyer will consider Seller’s request for changes only if such request is made in writing and directed to specific clauses in this order. No change shall be binding upon Buyer unless specifically accepted in writing.