AERO M4E1 THREADED UPPER RECEIVER FDE The M4E1 Threaded Upper Receiver features a new angular machined design that helps it stand apart from standard mil-spec upper receivers. This upper receiver features the same enhanced body profile as our M4E1 Enhanced Upper Receiver but is threaded to accept a standard AR15 barrel nut. It is forged from 7075-T6 Aluminum, precision machined to work with all mil-spec AR15 parts and includes the port door and forward assist pre-installed. The M4E1 Threaded Upper Receiver is designed to pair perfectly with our new M4E1 Lower Receiver, giving you a billet looking receiver set at a fraction of the billet price. Features: New enhanced forging that gives the upper receiver a "billet look" New picatinny profile that blends seamlessly with our Enhanced and ATLAS Series Handguards M4 Feedramps .250 takedown pin holes Includes threaded forward assist roll pin Includes port door and forward assist Includes: M4E1 Threaded Upper Receiver in Magpul FDE Cerakote Port Door and Forward Assist installed