Convenient kit contains the components you need to complete an AR-15 bolt and bolt carrier for installation in the rifle. Perfect for custom builds where bolt and carrier are obtained from different sources, and you need a firing pin, cam pin, and firing pin retaining pin to complete the assembly. Also a good idea to replace these critical parts when refurbishing existing rifles to help ensure reliability. Manufactured from high-quality steels, hardened as necessary, to mil-spec tolerances, and ready for installation. Installation instructions included.