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. It includes .250 takedown pin holes. NOTE: Requires charging handle, barrel, handguard, gas block, muzzle device, gas tube and BCG (Bolt Carrier Group) to complete.