The Angstadt Arms AA15 is a 7075-T6 billet matched receiver set for 5.56 NATO and .300 Blackout builds. Machined to perfection and finished in a beautiful Type 3 Mil-Spec hard coat black. 7075-T6 billet aluminum lower receiver Flared magwell for faster reloads Integrated, oversized trigger guard 7075-T6 billet aluminum upper receiver with shell deflector and slick side (no forward assist or dust cover) M4-style extended feed ramps for optimal feeding Threaded bolt catch screw Upper weight: 6.7 oz Lower weight: 9 oz Patent pending