AR57 ULT UPPER ASSEMBLY 12″ BBL 5.7X28

AR57 Ultra Light Tactical Upper Assembly 5.7x28mm; 12″ Barrel – 1:9 Twist Rate – Black Melonite Finish; Forged from 1 7075 T6 Monobloc Aluminum; 8620 Steel Alloy Bolt Carrier Buffer Tube & Flashider – Black Meonite Treatment Finish