ATI Alpha Maxx - 5.56x45mm Nato ATI Alpha Maxx AR-style Semi-automatic Firearm chambered in 5.56x45mm Nato, Featuring a black finish, Ventilated handguard, Picatinny rail, and muzzle device. includes a schmeisser 60 round magazine and a SIG Sauer Romeo5 Red-dot optic. Equipped with a textured pistol grip and buffer tube assembly.