C4 LED delivers 4,100 candela peak beam intensity; 90 lumens. 2-3 times brighter than high-flux LEDs. Parabolic reflector produces a concentrated beam with optimum peripheral illumination. Optimized electronics provide regulated intensity. Runs 1.5 continuous hrs. to the 10% output level. Includes 5 interchangeable keys to fit a wide variety of weapons. Rail clamp designed to rapidly attach/detach from side of weapon. One handed snap-on and tighten interface keeps hands away from muzzle when attaching/detaching. Ambidextrous momentary/steady On-Off switch. Body constructed of impact resistant nylon polymer. Face cap constructed of 6000 series machined aircraft aluminum with anodized finish. Borofloat high temperature glass lens. Waterproof to 1 meter for 30 minutes. IPX7 rated. Operating temperature: -40°F to +120°F. Powered one 3V CR2 lithium battery. Serialized for positive identification. 2.71 in. (6.88 cm).