The Fenix ALG-16 M-Lok Rail Mount is a great solution for mounting a flashlight to a rifle with a M-Lok guide rail. The quick release roller allows you to mount a flashlight for a secure fit. Made of hard-anodized aluminum, this rail mount is strong and lightweight, perfect for harsh conditions where durability counts. Hard-anodized, anti-abrasive finish. Patented roller allows for quick assembly and disassembly. Compatible with flashlight body diameters 23.5mm - 26mm with a head less than 40mm.