The Kel-Tec SU-16 series is designed, engineered and crafted to be the perfect everyday Sport Utility rifle. Differing primarily in barrel length and stock configuration, these gas piston operated, semi-auto rifles accept standard AR-15 magazines. This SU-16 features a pistol grip, accepts M4 style buttstocks (Not included) and has a threaded barrel. Firearm does not come with a case but does come with a Magpul 30-round magazine. Action GAS PISTON Barrel Length 16.0" BARREL Caliber 5.56X45MM NATO Capacity 30 ROUNDS Finish BLACK Muzzle Type THREADED Optic Mount 1913 PICATINNY Sights OPEN NOTCH Thread Pattern 1/2X28 TPI