(3) BUFFERS- These durable Neoprene Buffers are over 6mm thick and will outlast your stock buffer for thousands of rounds. They are a bit stronger than than the OEM buffers and are a necessary item to keep at least one spare. The constant battering by the bolt will wear down any buffer and may cause damage to the spring, back of your weapon and any related parts. (bolt assembly sold separately) This part number is for (3) Buffers. Fits all Semi Auto & SMG guns. Fits Mac-10 .45/9mm & Master Piece Arms .45 acp, Vulcan .45.