CMMG Lower Parts Kit AR15 - CMMG Gun builders kit includes most of the necessary parts to build up your lower group except the commonly upgraded parts. Does not include Trigger Guard, Fire Control Group and pistol grip. All parts meet or exceed Mil-Spec. Kit Includes: Bolt catch/roll pin Bolt catch plunger/spring Trigger/hammer retaining pins Safety, detent, & spring Magazine catch, spring, & release button Pivot/takedown pins, detents, & springs Buffer retainer/spring