Fortis Manufacturing's AR-15 556MM 12 inches M-LOK Night Rail Free Float System Handguard was designed to be easy to install and also to be able to mount with a full 360 degree of contact. Their new patent pending 2-piece barrel nut is one of a kind. They developed it from the ground up and the machining time it takes to make the barrel nut rivals the time making the actual rail. That's not to say the rail is simple to make. One look and you'll see that they really took time with this in design and development. What they ended up with is a rail that not only looks amazing but is still true to their lightweight brand. The barrel nut/mounting system keeps the rail performing even during the harshest of conditions.Features:Proprietary, patent pending 2-piece barrel nut that provides 360 deg contactFree float rail designM-LOK attachment points12.875 inches length