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 Manufactured with confidence and without compromise, the Super Duty MOD1 adds value to the platform while continuing the reputation for excellence. All of these technologies and advancements combine to bring to market a true next-gen upper for the AR-15 platform. The Super Duty Complete Upper from Geissele Automatics offers unmatched performance, accuracy and reliability.