This is a complete DPMS upper with Vortex Crossfire Hog Hunter 3-12x56 optic. Rainier Arms 18" barrel, Midwest Industries hand guard, BCM Gunfighter Charging handle. BCG is mil spec. Compensator needs replaced but will still shoot. The pain is rattle can. Scope is in great shape as it was just replaced from Vortex with their lifetime warranty. Bolt it on and start doing some shooting.