This is an NOS Holley carburetor dashpot, Ford part # B2A 9800-B.  It was used on Holley carburetors on Fords, Thunderbirds and Mercurys from 1952 thru 1959, including the 1957  factory dual quad or “E" model. It has the original metal front and back canister and the original accordian rubber dust boot.  This dashpot was never installed.  We charge actual shipping and will be glad to combine shipping on several auctions, or you would be welcome to pick them up at our shop.  Thanks!