Bravo Company, BCM MK2 Recoil Mitigation System, Mod 1, 8 Position Buffer Tube Complete Assembly, Matte Finish, Black, Includes T1 Buffer, M16A4 Rifle Action Spring, MK2 Receiver Extension, QD End Plate, Castle Nut, Fits AR RiflesWhether starting a new rifle build or upgrading an existing one the BCM MK2 recoil mitigation system offers less felt recoil while maintaining and improving reliability. Comes as a complete kit ready to mount on any AR pattern rifle. Features : 4. 7oz buffer weight offers Increased internal counterweight travel to reduce bolt bounce Internal spring to reduce noise of counter weight shifting and ensure more consistent weight placement Mil Spec M16A4