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 Finish, Flat Top Receiver, No Sights, 12" SAR3 Quad Rail, Dynacomp Muzzle Brake,No Mags STU5050-S2D