Spike's Tactical Complete Upper Receiver, 223 Rem/556NATO, 14.5" Barrel (16" OAL with Pinned Brake), Mid-length Gas System, Fits AR Rifles, Black, Flat Top Receiver, No Sights, 12" CRR Quad Rail, Dynacomp Muzzle Brake, No Mags STU5050-CQ2D
Determined at checkout.