LWRCI Complete Di Upper Receiver 5.56mm 16 inch Barrel 1-7 Twist Extended M-LOK Handguard Black 16in. 1in Cold Hammer Forged NiCorr-treated barrel sporting the weight reducing spiral fluting mated to a Monoforge Upper receiver. The soft-shooting mid-length gas system is mated to our innovative "keyless" DI Bolt Carrier for incredible reliability and performance. Specifications for LWRCI Extended 16 inch 5.56mm Complete Di Upper Receiver: Manufacturer: LWRCI Caliber: 5.56mm Barrel Length: 16 in Barrel Twist Rate: 1-7 Color: Black Magazine Included: No Features of LWRCI Extended 16 inch 5.56mm Complete Di Upper Receiver Direct impingement system chambered in 5.56 nato Enhanced di bolt carrier group Extended 13in mlok mlx s free-float rail 16.1in cold hammer forged nicorr treated fluted barrel Ambidextrous charging handle A2 flash hider Package Contents: LWRCI Extended 16 inch 5.56mm Complete Di Upper Receiver LWRCI ICDIU5B16MLXS: Complete Di Upper Receiver 5.56mm 16 inch Barrel 1-7 Twist Extended M-LOK Handguard Black 16in