The Geissele Super Duty MOD1 Upper features the latest in weapon technology available exclusively from Geissele Automatics. This complete upper chambered in 5.56mm features a nanoweapon-coated HUXWRX Flash Hider-QD muzzle device mounted to a Manganese Phosphate coated, CHF, Chrome Lined barrel. Geissele barrels are precision machined and cold hammer forged utilizing the highest quality materials at a state of the art facility in North Wales, PA. The Geissele length gas system and Geissele Super Compact Gas Block with bomb-proof installation ensures reliability and optimal performance in extreme conditions.