The Nitecore GM02 Pro is constructed from aero-grade aluminum alloy with HA III military-grade hard-anodized finish for rugged durability. A large stainless steel thumb nut alloys for easy adjustment and ensures stable mounting on a Picatinny rail. It can fit flashlights with a body diameter of 1 inch (25.8mm-26.5mm) and fits models like the Nitecore SRT7 SRT7i, SRT6i, MH12 Pro, and MH25 Pro.