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 – Laser engraved T-marks – Includes threaded forward assist roll pin – Includes port door and forward assist – Includes: – M4E1 Threaded Upper Receiver in Anodized Black – Port Door and Forward Assist installed