The Colt AR-15 Upper Receiver Assembly comes complete with Magpul adjustable flip-up rear sight, charging handle, bolt and bolt carrier assembly. The Colt AR-15 Upper Receiver also comes complete with A2 flash hider, M4 polymer handguard, and a barrel with a black parkerized finish. This Upper Receiver Assembly comes with a picatinny-style flattop rail for plenty of accessories, and is more than ready to offer maximum versatility.FeaturesMagpul Adjustable Flip-Up Rear SightA2 Flash HiderM4 Polymer HandguardBlack Parkerized Barrel Finish