The Wilson Combat M-Lok AR handguard system has been designed to be the lightest, strongest and most versatile compact free-floating rail system. Our precision machined three, six and nine O'clock M-Lok positions enable fast, easy mounting of multiple shooting accessories popular across the shooting industry. In addition to a lighter, sleeker rail profile, the barrel nut design was retained from the original T.R.I.M rail to make it simple for users to easily swap the older Wilson Combat T.R.I.M rail design with this new M-Lok version. Simple, 5 minute installation with common hand tools, easily removed or replaced in the field. 1.350" internal diameter is compatible with most low profile gas blocks.