Wilson Combat Small Parts Kit, Fits Wilson Combat AR10 Billet Receiver, Black, Includes - Wilson Combat Bullet Proof Bolt Release WC-10, Bolt Catch Screw for WC-10 Billet Lower, Bolt Catch Plunger, Bolt Catch Roll Pin, Bolt Catch Spring, Magazine Catch, Magazine Catch Spring, Magazine Catch Button, WC-10 Pivot Pin, WC-10 Takedown pin, 2x Pivot/Takedown detents, 2x Pivot/Takedown detent springs, Safety Detent, Safety Detent Spring, Semi-auto Safety selector (Right Hand) and 2x Trigger/Hammer Pins TR-LOWERK-10