This complete upper includes our ATLAS S-ONE Handguard! The S-ONE line of handguards are designed with size and weight in mind, providing the perfect addition to your lightweight build. Our proprietary ATLAS attachment system is a durable and dependable mounting platform, maintaining a slim profile while still providing the strength and stability customers have grown to love from Aero Precision handguards.Includes:M4E1 Threaded Assembled Upper Receiver10.3" M-LOK ATLAS S-ONE Handguard12.5" 5.56 Government Profile CMV Barrel, Carbine LengthLow Profile Gas Block and Carbine Length Gas TubeAR15 A2 Birdcage Flash HiderProduct comes assembledThis complete upper does not include BCG or Charging Handle. These products may be selected as add-ons under the FINISH YOUR BUILD tabFeatures:New enhanced forging that gives the upper receiver a "billet look"New picatinny profile that blends seamlessly with our Enhanced Series HandguardsM4 Feedramps.250 takedown pin holesLaser engraved T-marksIncludes port door and forward assist installed