A.R. Coated Glass Optics, patent-pending 360° LED optical system delivers a focused beam of light precisely where you want it. 65' effective range. Water resistant. Lifetime LED bulb. AA battery included. 3 position twist tail cap (constant on, constant off, momentary on). 3.9" long. Aircraft aluminum hard-coat anodized body. Intelligent power regulation. Up to 10 hours burn time off one AA battery.