Features Smoother internal transition improves gas flow Potentially boosts FPS and increases performance Direct replacement rubber magazine gasket 2 replacement gaskets per pack Manufacturer: Nine Ball / Laylax Specifications: Compatibility: For Tokyo Marui MP7, M&P9, HK45, XDM-40, PX4, Warrior, Colt Government, MEU, Detonics .45 and USP Series Airsoft GBB PistolsMaterial: Rubber About Prometheus / Laylax Providing products in the Japanese market for the better part of 20 years, Laylax is well known for their high manufacturing quality and precise tolerances. Their tried and true parts and accessories have led them to be the leader in Japanese airsoft engineering.