The Spike's Tactical Standard Lower Parts Kit supplies the small parts needed to finish an AR-15 lower in 5.56. It ships with the complete fire control group and an A2 pistol grip, so the kit covers the internal components and grip in one package. Features: Complete AR-15 lower parts kit Fire control group: trigger, hammer, disconnector, and springs (standard mil-spec single-stage) Safety selector with detent and spring Bolt catch assembly Magazine catch assembly Trigger guard A2 pistol grip with screw Black, made in USA Fits standard mil-spec AR-15 lower receivers. The takedown and pivot pin set is not included with this kit.