This impressive little powerhouse runs on only one AAA battery (included) and still puts out 75 lumens for up to one hour. Near to far focusing options with the Advanced Focus System are possible because of a patented combination of a reflector and lens to create a light system that provides both a focused beam for long-distance needs and a spill beam for up-close reading. Rapid Focus™ technology allows you to go from reading to searching by simply moving a sliding bezel with your thumb. One LED. Length: 3.66". Weight: 1.48 oz.