Another item from X-Fire/PDI... "Commonly-used gun in Video games 'Bio Hazard' / Tokyo Marui M92F's Sear For TM M92F custom sear. Made of Iron(S45C) , all CNC machined and black oxide finish. If you want to keep it clean, please do maintenance to prevent from rusting. For using Custom Hammer, the normal sear is made of zinc die-cast. It is undurable material. The cycle of shooting change of sear's shape. PDI's sear is made of S45C, so it enhances durability."