Yankee Hill Lightweight 4 Rail AR-15 Mid-Length Forearms utilize our anti-rotation screws to insure that the forearm stays solid even under strenuous use. Perfect for use with forward grips and optics. The Lightweight Forearm in Mid-Length features mounting points for Swiveling Sling Studs (YHM-9469), Mil. Spec. Picatinny rails, and they accept Forearm End Caps. The barrel nut and forearm tube are made of aircraft quality aluminum and hardcoat anodized to Mil. Specs. The jam nut is made from steel and plated a matte black to match. All assemblies include: one jam nut, one barrel nut, 2 anti-rotation screws, and one forearm tube. The overall length of the Mid-Length Forearm is 9.2 inches and weighes 12.4 ounces.