CMMG A1 Stock Kit is a black synthetic fixed-length A1 buttstock kit made from high-strength polymer, designed for AR-15 rifle-length buffer systems. Features a rear storage compartment and sling mount. Kit includes the A1 rifle-length buttstock assembly, CMMG A1 receiver extension, rifle buffer assembly, and rifle action spring. Backed by CMMG's Lifetime Quality Guarantee. Safety note Follow all manufacturer installation instructions. Verify proper function and secure mounting before use. Comply with local firearm laws and regulations.