M4 (T.Marui) CNC Steel Lightweight Bolt B

This steel lightweight Bolt B (part No.133), which is made by precision CNC process, and steel screw (part No.134) set is specially made for M4 (T.Marui) GBB.  The steel lightweight Bolt B is only 7g heavier than the original part.  Therefore, it has almost the same recoil shock as the original part does, but the strengthen construction provides outstanding durability and the smooth finishing minimizes friction around the buffer tube.