TROY Industries Battle Rail, 15 High-Profile SOCC Rail, Fits AR, 308 Win, M-LOK, Aluminum, Black SRAI-SR3-15BT-00 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.