Geissele Automatics Super Duty MOD1, Complete Upper Receiver, 556NATO, 16" Barrel, 1:7 Twist, HUXWRX Flash Hider-QD 556, 15" SMR MK16 M-LOK Free Float Handguard, Geissele Airborn Charging Handle, Nanoweapon Reliability Enhanced Bolt Carrier Group, Fits AR-15, Anodized Finish, Black 08-548B