The Gen 2 Balios-lite 10.5 5.56mm complete upper receiver offers the end user an assembled system that is ready for lightweight needs. Each assembled upper starts with a Balios-lite stripped upper receiver. We then add our titanium gas block on the appropriate length barrel and finish the assembly with our Gen 2 Balios-lite rail titanium barrel nut and our titanium T3 compensator. Our proprietary rail attach system does not need timing provides for an extremely solid lock up and tight joint to the upper receiver and has recessed fasteners for smooth clean feel. These uppers are perfect for those who are looking to do an SBR Pistol or suppressed 5.56mm build. Our full mass carrier is included as well as a BCM-Mod4 charging handle. - Barrel Material: 4150 Chrome Moly Vanadium - Twist Rate: 1:7 inches - Finish: QPQ Nitride - Muzzle 1/2 x 28 thread - Carrier: Full mass QPQ Nitride body and gas key Stainless tail - Bolt: 9310 QPQ Nitride body and extractor Cryo'd MP tested - 7075 enhanced charging handle BCM-Mod 4 - Includes titanium T3 Comp - Weight: (2lbs 13.9oz M-Lok) (2Lbs 14.0oz KeyMod)