This 16″ Dissipator M4 Profile Upper Receiver Barrel Assembly is complete, ready to snap onto your lower and take to the range. The accurate 16” barrel is chrome lined and machined from 4150 Chrome Moly Vanadium 11595E steel rifled 1 x 9” RHT. It features a low profile gas block functioning in the carbine position under the rifle length handguards. An A2 Flash Suppressor, and standard A2 Front Sight in the rifle length position are fitted – the longer sight radius of the rifle sight placement enhances accuracy. The assembly includes premium quality, rifle length handguards molded from a fiberglass composite for heat resistance in sustained fire – they will not deform when subjected to high barrel heat. The machined aluminum flat top Upper Receiver is complete with Bolt, Bolt Carrier Assembly, Charging Handle, Forward Assist, Ejection Port Cover, and Removable A4 Carry Handle with 300 – 600 meter Dual Aperture Rear Sight adjustable for windage and elevation.