The FMK AR-1 Polymer Lower Receiver is a high-quality component designed for AR-15 enthusiasts. Manufactured in the USA from a proprietary composite polymer, this receiver provides superior strength and unmatched durability while remaining extremely lightweight at just 4.30 oz. The AR-1 is built to withstand extreme conditions and bounces back to shape when others may dent or break. It accepts all standard MIL SPEC uppers up to .50 Beowulf and is compatible with most current AR-15 lower parts kits, grips, and stocks. With a lifetime warranty, you can trust in the quality and performance of the FMK AR-1 Polymer Lower Receiver for your next build.