"Inspired by the combat-proven M4, the Military Armament Corporation (MAC) Model 1014 Breacher Semi-Auto Shotgun delivers military-grade performance and reliability. Featuring a self-regulating gas piston operating system, the 1014 reliably cycles a variety of loads while running cleaner than other semi-autos. Like the M4, the MAC 1014 features a Picatinny optics rail, adjustable ghost ring rear sight, and front post sight with white dot. This model also adds a pistol grip and fixed position butt-stock. The 18.5"" barrel uses a Benelli/Mobil-pattern choke tube system. Polymer forend and stock with rubber butt pad. Compatible with aftermarket M4 components. Mfrs. 1-year warranty. Modeled after the Benelli M4 Self-regulating gas piston system 18.5"" barrel uses Benelli/Mobil-pattern chokes Polymer stock and forend Rubber butt pad Picatinny optics rail Adjustable ghost ring rear sight/post front Compatible with aftermarket M4 components"