Combining carbine-like ballistic performance and compact size, this 8" BANSHEE(TM) upper group is what you need for the ultimate 9mm AR. Not only does this 9mm upper utilize CMMGA(R)'s radial delayed blowback technology, but shooters also have a number of lower/magazine pairing options. 9mm Radial Delayed Blowback uppers are designed exclusively to work with CMMG MkGs, Mk17, or mil-spec AR15 lowers using our 9mm Conversion Magazines. Available in different Cerakote finishes, all CMMGA(R) Upper Groups come complete with bolt carrier group and ZEROED(TM) accessories including:Features:Platform: Mk4, Mk9, Mk17, MkGsCaliber: 9mmOperating System: Fixed Ejector Radial Delayed BlowbackBarrel Length: 8Barrel Twist: 1:10Barrel Contour: MTBarrel Material: 4140CM, SBNBarrel Twist: 1:10Muzzle Device: CMMG ZEROED Linear CompensatorMuzzle Thread: 1/2 X 28Gas Port Location: N/AGas Block: N/AUpper Receiver: Billet 6061 T6 AluminumHand Guard: CMMG EML7 M-LOKFinish: Cerakote StandardCharging Handle: CMMG ZEROED AmbiWeight: 3.0 lbsLength: 16.5"