Spike's Tactical Lower Receiver Parts Kit Without Fire Control Group/Trigger Group, 223 Rem/556NATO, Includes Safety Selector, Bolt Catch, Magazine catch, Billet Magazine Catch Button, Front Pivot Pin, Rear Take Down Pin, Aluminum Trigger Guard w/Spring Loaded Detent, Bolt Catch Spring, Disconnect Spring, Magazine Catch Spring, Safety Selector Spring, Buffer Retainer Spring, Safety Selector Detent, Bolt Catch Plunger, Buffer Retaining Pin, Bolt Catch Roll Pin, Trigger Guard Roll Pin, A2 Pistol Grip, 1/4x28 Allen Cap Screw, Star Lock Washer for A2 Grip Screw SLPK100.