The AR-15 Assembled Upper receiver comes with the port door and forward assisitalready installed. Forged from 7075-T6 aluminum, this assembled upper is precision machined to mil-spec M16/M4 specifications and features M4 feedramps. Match this upper with one of Aero’s AR15 lower receivers for a solid and dependable fit. This upper features M4 feedramps, .50 takedown pin holes, Laser engraved T-Marks and includes a port door and forward assist. This assembled upper comes in anodized black.