Universal Parts Kit Includes: 1 x Receiver Screw (short) 1 x Regulator/air Valve/puncture Valve O-ring 1 x Air valve O-ring (large) 2 x Firing Valve O-ring 1 x Front Bolt O-ring 1 x Air valve O-ring 1 x Puncture Valve O-ring 1 x Gas Line/Air fitting O-ring 1 x Barrel adapter O-ring 1 x Front bolt buffer O-ring 1 x CO2 cap O-ring 1 x Regulator Piston O-ring 1 x Pressure bleeder O-ring 1 x Ball Latch 1 x Puncture pin 1 x 12 Gram puncture seal 1 x Puncture pin cap 1 x Receiver nut 1 x Breech window 1 x Air fitting screw 1 x Regulator pin