Geissele 08-244B Super Duty 5.56 NATO 10.3" 1:7" CHF Bbl Black Stripped Upper Receiver w/9.3" M-LOK MK16 SMRThe Super Duty Stripped Upper offers the craftsmanship and quality that a Geissele products are known for. It comes equipped with Geissele’s Super Modular MK16 Rail which attaches to the upper receiver with an enhanced barrel Nut, anti-rotation tabs and set screws, ensuring the rail will not pivot even under extreme conditions. The MK16 features M-LOK mounting locations in the 3 o’clock, 6 o’clock, and 9 o’clock positions, as well as in the upper and lower 45° positions for maximum customization, and a 12 o’clock picatinny rail accommodates the installation of optics and other picatinny-based accessories. In addition, the Super Duty Stripped Upper is outfitted with a Manganese Phosphate coated, CHF, Chrome-Lined barrel. The barrel is precision machined and cold hammer forged at Geissele’s state-of-the-art facility in North Wales Pennsylvania, and utilizes the best materials available. Features of the Super Duty Stripped Upper: Super Modular MK163 o’clock, 6 o’clock, and 9 o’clock M-LOK mounting points12 o’clock picatinny railManganese Phosphate coated, CHF, Chrome-Lined barrelNOTE: All NFA regulations apply Geissele Super Duty 5.56 NATO 10.3" 1:7" CHF Bbl Black Stripped Upper Receiver w/9.3" M-LOK MK16 SMR 08-244B