Aero Precision M5 Lower Parts Kit, For AR10, Includes Takedown/pivot Spring, Takedown/pivot detent, M5 .308 Takedown pin, M5 .308 Pivot pin, M5 .308 Bolt Catch, Bolt Catch Spring, Bolt Catch Buffer, Bolt Catch Roll pin, Safety Selector, Safety Selector Spring, Safety Selector Detent, Buffer Retainer, Buffer Retainer Spring, Magazine Catch Body, Magazine Catch Spring, and Extended