Outerwild AR15 Premium Line Handguard 7in M-Lok Black Anodize. Unlike many manufacturers who simply cut holes and slots in their extrusion we machine every surface of the exterior to ensure a uniform and flat surface. Outerwild's 4140 steel barrel nut does not need to be indexed for gas tube clearance and easily installs with a standard castle nut wrench. Specifications for Outerwild AR15 Premium Line Handguard: Manufacturer: Outerwild Color: Black Finish: Anodize Fabric/Material: 6061-T6 Aluminum Gun Make: AR Platform Gun Model: AR-15 Gun Type: Rifle Gun Rail: M-LOK Weight: 10.8 oz Inner Diameter: 1.25 in Mount Type: M-LOK Package Contents: Outerwild AR15 Premium Line Handguard Stainless Steel Barrel Nut Screws Outerwild 4005-1009-104-O: AR15 Premium Line Handguard 7in M-Lok Black Anodize