Using a 3-Watt 100,000-hour T bin Luxeon Led,no need for a fragile incandescent bulb Maximum brightness:80 Lumens One 3V CR123A or two 1.5V AA battery three stage output. 4-hour working time(1.0-hour peak brightness) 153mm(L)*26mm(D)or 88mm(L)*26mm(D) Constructed of aircraft grade aluminum Type III hard anodized finish,highly durable Waterproof Toughened ultra clear glass lens with AR coating Push-button tail cap switch