The AR15 Assembled Upper Receiver comes with the port door and forward assist already 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. FEATURES: M4 Feedramps .250 takedown pin holes Laser engraved T-marks Includes port door and forward assist SPECS Platform: AR15 Material: Machined from 7075-T6 forged aluminum Select Your Finish: Anodized Black Compatibility: Works with standard AR15/M16 components Weight(s): 8.35oz Mfg: Aero Precision