SLR 14.87 inch HELIX M-LOK .308 High Profile Handguard Black 308H-HELIX14.87ML. 45 inch Internal Diameter. SLR's most lightweight handguard design. DPMS High Profile. Mil-Spec Hardcoat Anodize. 7075 Barrel nut w/ Hardcoat Anodize. Free Floating Design....