These American Tactical Import (ATI) Complete Upper receivers feature a 15" free-floating MLOK rail Phosphate BCG and 16" barrel. Perfect for a new AR-15 build the ATI MilSport line is compatible with any MilSpec parts or lower receiver you wish to work with. You can drop this upper right onto a complete lower and get right to the shooting range if you wish; it ships with a low profile gas block flash hider charging handle complete bolt carrier group barrel and upper receiver assembly fully assembledFeatures: 16" barrel 1:8 twist Phosphate Bolt Carrier A2 flash hider Micro Gas block 15" free-float MLOK accessory rail 7075 T6 Aluminum Upper