The MEC V piston head set for gas blowback pistols is an improvement over the stock pistol piston head, especially those with metal slides. This rubber piston head is designed to improve the airtightness and withstand high impact pressure. The “v shape” ramp cut at the base of the inner wall of the piston head provides fast responsiveness on air-sealing. The better sealing that the MEC V piston head provides translates to better-felt recoil and noticeably better gas efficiency. These piston heads have two sizes: 13 to 14mm or 14 to 15mm fit into multiple GBB pistol models with 13 to 14mm or 14mm to 15mm nozzles. Each size also comes with two different hardness, the black one (60 degree) for colder weather or for use with regular power gas and the purple one (70 degree) for warmer weather or use with high power gas.