UPPER RECEIVER KIT BLACK!GUNTEC AR15 STRIPPED BILLETGUNTEC AR15 STRIPPED BILLETUPPER RECEIVER KIT BLACK! FEATURES: . 223 5. 56 Cal T6 6061 Billet 1913 Picatinny Rail Flat Top Manufactured From Solid Block of Billet Aluminum M4 Feed Ramp Will Match up w any brand lower receiver Accepts Mil Spec ejection port door kit & forward assist kit (Included) Slim profile shell deflector Complete kit includes upper receiver, Complete BCG, ejection door assembly, charging handle, forward assist assembly