Blue Tail light LED for high visibility in smoky conditions. A great light for fire and rescue crews, military and industrial users. Bright, powerful LED and specially engineered reflector with C4 Photonic Crystal technology almost triples the brightness and creates an intense beam that pierces the darkness. You get long-run times and indestructibility of an LED with a new level of brightness that leaves other LEDs in the dark. C4 technology approximates the range and brightness of a Xenon bulb.