Primary Weapons Systems MK111 MOD1-M Upper Receiver .223 Wylde 11.85in bbl Black. 85in Barrel .223 Wylde 3-Setting Adjustable Gas System Triad556 Specifications for Primary Weapons Systems MK111 MOD1-M .223 Wylde 11.85in bbl Upper Receiver: Manufacturer: Primary Weapons Systems Caliber: .223 Wylde Barrel Length: 11.85 in Muzzle Device: PWS Triad 556 Finish: Matte Color: Black Condition: New Magazine Included: No Package Contents: Primary Weapons Systems MK111 MOD1-M .223 Wylde 11.85in bbl Upper Receiver Primary Weapons Systems 18-M111UA0B: MK111 MOD1-M Upper Receiver .223 Wylde 11.85in bbl Black