The Geissele Super Duty MOD1 5.56 NATO 11.5" Complete Upper Receiver Group 08-544B is a compact upper built around an 11.5-inch cold hammer-forged barrel with a 1:7 twist and chrome-lined bore and chamber. The black-finished setup includes a 10.5-inch MK16 Super Modular Rail, Geissele Airborne Charging Handle, pinned low-profile gas block, and HUXWRX Flash Hider QD 5.56.

The 11.5 Geissele barrel uses cold hammer-forged construction for a durable bore and rifling profile. Chrome lining covers both the bore and chamber, adding corrosion resistance and helping the barrel stand up to regular use. The 1:7 twist is suited to a broad range of 5.56 NATO projectile weights.

Up front, the 10.5-inch MK16 Super Modular Rail gives the upper a clean, compact profile while providing M-LOK mounting slots for compatible accessories. Its length closely follows the barrel, keeping the handguard configuration well matched to the 11.5-inch barrel.

Gas management is handled by a Geissele pinned low-profile gas block. The muzzle is fitted with a HUXWRX Flash Hider QD 5.56, while the included Airborne Charging Handle provides the charging interface. These components come installed as part of the complete upper rather than requiring separate assembly.

The black finish gives the Geissele Super Duty black configuration a consistent appearance from the receiver through the handguard and barrel components. The result is a complete 5.56 NATO upper with a short barrel, modular handguard, and a selection of Geissele components already configured together.

Features:

• 5.56 NATO chambering
• 11.5-inch cold hammer-forged barrel
• 1:7 twist rate
• Chrome-lined bore and chamber
• 10.5-inch MK16 Super Modular Rail
• M-LOK accessory mounting
• Pinned low-profile gas block
• Airborne Charging Handle