The sleek, modern designs of Aim Sports' AR-15 free-float M-Lok handguard offers such features as a U.S.-made steel barrel nut, and built-in, machined anti-rotation tabs. Cut for weight reduction and meticulously engineered to be ultra light, this system retains the utmost in robust construction, with a 1913-Picatinny top rail mounting system and seven rows of M-Lok mounting surface for ultimate modularity attachment points for all your M-Lok accessories. The AR-15 free-float M-Lok handguard works with low profile gas blocks. This model is 13.5" and weighs 0.77 ounces.