FAB Defense M4 Conversion Kit Chassis is a tactical upgrade for Ruger 10/22 rifles (standard and bull barrel), converting them to a collapsible, side-folding M4-style chassis system. Constructed from durable, lightweight fiberglass-reinforced synthetic polymer in black finish. Features a collapsible buttstock with 5 length options, an ergonomic finger-groove pistol grip with contoured backstrap for reduced wrist fatigue and improved trigger operation, and 1913 Mil-Std Picatinny side and lower rails for mounting accessories. Includes Quick-Detach sling swivel sockets on both sides. Quick, drop-in installation with no gunsmithing required. Backed by a 25-year limited warranty. Safety note Follow all manufacturer installation instructions. Verify proper function and secure mounting before use. Comply with local firearm laws and regulations.