Original Used H4 S.U. 1.5 inch Carburettor Pistons 3182/1 and matching suction Chambers To Suit MG TD TF MGA. The piston moves freely up and down, the pistons don't have a needle or spring, both suction chamber have needle screw and a damper but one has no valve. Both are in good condition at some point in time they have been cleaned. We have two of these one chamber is stamped 1 and the other chamber is stamped 2, so are quite likely a pair from the same car so are being sold as a pair. Used Condition - Please see photo(s) - they form part of the description.