Our 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. – This lower parts kit does not include the fire control group pistol grip or trigger guard. – Includes: – Takedown/pivot Spring – Takedown/pivot detent – Takedown pin – Pivot pin – Bolt Catch – Bolt Catch Spring – Bolt Catch buffer – Bolt catch roll pin – Safety Selector – Safety Selector spring – Safety Selector detent – 4-40 Set Screw (for threaded takedown pin detent hole) – Buffer retainer – Buffer retainer spring – Magazine catch body – Magazine catch spring – Magazine catch button