The Geissele super modular rail MK16 is engineered for unparalleled performance to meet the needs of the most demanding shooters. It attaches to your AR-15 upper using an updated version of the proven Geissele barrel nut design, making installation and maintenance straightforward while providing superior rigidity. Anti-rotation tabs and set-screws ensure that the rail remains securely in place, even under extreme conditions. Featuring an M1913 picatinny rail on top and M-LOK slots on every quadrant, the MK16 offers maximum customization for all your accessories. Precision machined from 7000 series aluminum for its strength, rigidity and lightweight properties, it is finished with a durable Type-3 hard coat anodized coating. Available in a 13.5 inches length, the super modular rail MK16 M-LOK, NSN# 1005-01-672-4794, has been adopted by USASOC for the URG-I program (upper receiver group Improved).