Billet receivers are 1" shorter than standard AR-15; Upper and lower receivers are billet machined aluminum alloy; Alloy Mil-Spec anodized finish; Compatible with Glock Style mags; M-Lok free float handguard; 8" Barrel, nitride 4150 Chromoly steel, 1:10 twist (1/2"x28 t.p.i.); KAK Pistol Brace; AR-15 Configured Last Round Bolt Hold Open, AR-15 Configured Safety Selector, AR-15 Configured Magazine Release; Comes with one 31 round mag; Compatible with 9mm approved 1/2"x28 T.P.I. muzzle devices and suppressors