The TWM-850XLS Xtreme Lumens Tactical Weapon-Mounted Light uses an LED rated at 850 lumens working in conjunction with a high-efficiency deep parabolic reflector to create a usable beam of light rated at 245 meters. This weapon light features a unique and completely Dual Dependent Toggle Switch on each side of the light to operate the momentary-on and constant-on lighting modes. The housing of the TWM-850XLS is constructed from aircraft-grade 6061-T6 Aluminum with a Glass-filled Nylon Polymer battery door and toggle switches. Power comes from two included CR123 batteries. (Not compatible with rechargeable batteries.)