Kit includes the following: Takedown Pin, Pivot Pin, Pin Detent x2, Detent Spring x2, Ambidextrous Safety Selector, Safety Detent, Safety Detent Spring, Buffer Retainer, Buffer Retainer Spring, Bolt Catch, Bolt Catch Plunger Spring, Bolt Catch Plunger, Bolt Catch Roll Pin, Bolt Catch Set Screw (6-32, compatible with Lantac, Aero and other lowers), 1/16th Allen Key Head, Mag Catch, Mag Catch Spring and Mag Catch Button