The Gerber Infinity Ultra Task Light (Green) runs on one AA battery for up to 60 hours. The white L.E.D. bulb never burns out and can cast a beam 30 ft long. The body of the flashlight is made of anodized aircraft aluminum and is water proof thanks to the o-rings integrated into the caps. The Infinity Ultra Task Light weighs only 2.2 oz and is perfect for gear packs where space is limited, but big light is a must.