This AR-STONER AR-15 Upper Receiver provides style, function, affordability to your AR-15 Pistol. The A3 upper attaches to virtually any standard AR-15 lower receiver. Machined with M4 feed ramps, this upper features an M-Lok handguard. M-Lok Handguard slots allow mounting of popular M-Lok compatible accessories directly to precision cutouts with a sleek design that does not sacrifice strength or ergonomics. IncludesForged upper receiver with M4 feedrampsBolt Carrier Group HPT/MPI nitride finishLow profile .750 gas blockGas tubeSlim Mlok Free Float Hand GuardCharging handleDust coverForward assistA2 flash hider