Out of stock $2,220.00 HK MR556 A4 Upper Receiver, 223 Remington/556NATO, 16.5" Barrel, Threaded 1/2X28, M-LOK Handguard, Anodized Finish, Black, Fits AR-15 Lower Receivers, Includes Bolt Carrier Group, Charging Handle, Buffer Weight and Buffer Spring 51000384
