Small and mighty, the M1 flashlight has the means to take on the elements when necessary. It runs on a single CR-123 battery (included), giving it an extremely long shelf life (10+ years) and maintains high voltage for plenty of power when you need it. This type of battery also works well in extremely cold temperatures where standard batteries can drain quickly. Smart Light Technology™ allows you to choose from different settings in order to conserve battery power. 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. Puts out 27 lumens for approximately up to five hours on low power. Puts out 150 lumens for up to three hours on high power. One LED. Length: 3.82". Weight: 2.75 oz.