Diamondback 9X1945M50B984NFR OEM Replacement 9mm Luger 4.50" Black Nitride 4150 Chrome Moly Vanadium Steel Replace Your Barrel, Or Finish Your Build With This 4.50" Black Nitride Barrel From Diamondback! Made Of 4150 CMV. Length: 4.50" Model: OEM Replacement Twist: 1:9.84" Finish: Nitride