The Kel-Tec SU-16C is a semi-automatic rifle chambered in 223 Rem5.56 NATO and it is compatible with appropriate AR-15 magazines. The SU-16C has a 16 threaded barrel adorned with an adjustable rear peep sight and a A2 style post front sight. A picatinny rail allows users to attach their choice of optics. The SU-16Cs polymer handguard also folds down into a bipod while the stock folds up for easier transport of the rifle. Details KEL-TEC SU-16 SEMI AUTO 223 REMINGTON5.56MM NATO 10 1 ROUNDS BLACK