TROY, BattleRail, 4.5" Low-Profile SOCC Rail, Fits AR, 9MM, M-LOK, Aluminum, Flat Dark Earth Lightweight Mil-Spec Anodized M-LOK cooling holes Mounts to standard barrel nut Troy's SOCC BattleRails with M-LOK cooling holes are narrow, sleek and provide exceptional balance and controllability. Lightweight with an ultra-low profile, snag-free design, they are ideal for close quarters maneuverability. Machined from hardened aircraft aluminum with stainless steel components and finished in Mil-Spec hardcoat anodizing, they mount to a standard barrel nut.