The CMMG AR-15 Lower Parts Kit has everything needed to populate a stripped mil-spec AR-15 lower receiver, including the fire control group and a pistol grip. Use it to finish a new build, or keep it on the bench as a source of spare springs, pins and detents. All parts meet or exceed mil-spec, so they fit the standard pockets and pin holes of a mil-spec lower, and the trigger group gives you a standard single-stage pull. Features: Trigger, hammer, disconnector, and trigger/hammer springs Trigger guard Safety selector Bolt catch with spring and plunger Magazine catch, spring, and button Pivot and takedown pins with detents and springs Buffer retainer and spring Pistol grip included All parts meet or exceed mil-spec Fits mil-spec AR-15 stripped lower receivers chambered in .223/5.56. The buffer tube, buffer, spring and stock are not included. After assembly, function-check the safety in both positions, trigger reset and hammer follow before live fire.