This carrier is designed for Picatinny rail mounted weapon lights, such as the M-3 and M-6 family of lights, as well as some of the other smaller models. The belt clip allows use with any standard width pants belt. The M-3 Carrier is designed to lock the switch in the off position, preventing it from accidentally turning on while you are wearing it. Or, you can carry the light in the lens down position and it will protect the lens from damage. The high-strength Carbon-Fiber Composite ensures years of service.