This complete upper receiver features the same tried-and-true construction and aesthetics as our M4E1 Threaded Upper Receivers, without provisions for a forward assist. The included ATLAS S-ONE Handguard is designed with size and weight in mind. Featuring a trimmed down top rail to help minimize weight and overall profile. 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.

• M4E1 Threaded Upper Receiver, No Forward Assist
• 15" ATLAS S-ONE Handguard
• 16" 5.56 CMV Barrel
• Low Profile Gas Block and Mid-Length Gas Tube
• Port Door Assembly
• A2 Flash Hider
• This complete upper receiver does not include BCG or Charging Handle.