The AR15 Assembled Upper Receiver comes with the port door already installed. This specific model does not have forward assist provisions. 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 our AR15 lower receivers for a solid and dependable fit. M4 Feedramps .250 takedown pin holes Lazer engraved T-marks No forward assist provisions Port door installed AR15 Assembled Upper Receiver Without Forward Assist in Anodized Black Note: The no-forward assist upper receivers use a custom forging designed to work specifically with mil-spec port Mfg: Aero Precision