Aero Precision's lower parts kit helps you to build a custom AR15 from the ground up. Mil-spec dimensions and coating ensure the highest quality and correct component interface. Their upgraded Enhanced Lower Parts Kit features a Magpul MOE Grip and Aero Precision Billet Trigger Guard. Takedown/pivot Spring Takedown/pivot detent Trigger/hammer pin Takedown pin Pivot pin 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 Billet trigger guard Trigger guard roll pin Mfg: Aero Precision