AR-15/M4 Mil-Spec Lower Parts Kit (Less Trigger, Less Grip) 1.Bolt Catch 2.Bolt Catch Plunger 3.Bolt Catch Spring 4.Bolt Catch Roll Pin 5.Mag Release 6.Mag Release Button 7.Mag Release Spring 8.Buffer Retainer Spring 9.Safety10.Buffer Retainer11.Safety Detent Spring12.Safety Detent13.Trigger Guard14.Trigger Guard Roll Pin15.Takedown Detent Springs16.Takedown Detents17.Takedown PinsItem Number:08-134