9mm JG-9 upper receiver with mlok hand guard, 9mm bolt carrier group, JG 9mm 4150 chrome moly vanadium steel barrel, JG ambidextrous charging handle and JG knurled 6 point directional compensator includedNOTE: Some rail systems that use anti-rotation tabs may need slight modification to fit this upper. It is designed for flush mounting rails and standard hand guards. Specifications for Jacob Grey Custom 9mm Complete Upper Assembly: Color: Black Finish: Class III Type 2 Hard Coat Anodized Fabric/Material: 7075-T6 Caliber: 9mm Caliber Barrel Twist Rate: 1-10