The Midwest Industries 12.625" Slim Line Rail is a high quality, lightweight free float M-LOK hand guard. Features: 4140 Heat Treated Barrel Nut Barrel Nut and Wrench Included Features Patented 4140 Heat Treated Torque Plate 12.625" overall length 10.3oz Installed Weight 6061 Aluminum Type 3 Hard Coat Anodized MIL-STD 1913 Picatinny Top rail Two Integral Anti-Rotation QD Sling Sockets Super Slim 1.5" Outside and 1.3" Inside Diameter Three Sides of M-Lok 5-Slot Polymer M-Lok rail included Fully Dehorned and Deburred 100% Made in USA