The Rosco Forged AR-15 Upper Receiver comes with the forward assist and port door installed. This upper starts with high-quality 7075 T6 aluminum forgings, precision machined to mil-spec dimensions, giving you maximum compatibility with mil-spec and aftermarket parts and accessories, offering superb strength and versatility for building a rifle configured exactly the way you want it. Machined from Forged American Made 7075-T6 aluminum Matte Black Mil 8625 Type 3 Class 2 Hard Coat Anodize Compatible with all Mil-Spec parts kits Precision-machined to M16/M4 specification and features M4 feed ramps