SureFire Saint LED Headlamp Virtually indestructible LED emitter regulated to maximize output and runtime Proprietary refractive optic produces a smooth, wide beam optimized for your field of vision Three 123A Lithium Batteries or Two AA-Alkaline Variable light-output dial controls levels from 0 to 100 lumens High-strength aerospace aluminum body, Mil-Spec hard-anodized for extreme durability Dual-fuel battery pack utilizes one, two, or three 123A lithium or two AA alkaline batteries