FAB Defense GL-Shock CP Buttstock is a recoil-reducing stock for AR-15/M4/M16 platforms, featuring a patented shock-absorbing mechanism with a built-in premium chrome silicon alloy spring and an adjustable cheek rest. Compatible with both Mil-Spec and Commercial aftermarket buffer tubes via its patented Anti-Rattle Mechanism. Made from Mil-Spec reinforced composite polymer in matte black finish, OAL 7.08, height 5.23, width 2.59, weighing 14.07 oz. Features a ribbed non-slip rubber butt pad, quick-operated inversed positioning lever, watertight battery storage for two CR123A/AA batteries, and QD sling swivel connectors on both sides. Safety note Follow all manufacturer installation instructions. Verify proper function and secure mounting before use. Comply with local firearm laws and regulations.