Using a 3 Watt 100,000-hour TX0 or TW0 bin Luxeon Led,no need for a fragile incandescent bult. Maximum brightness:80 Lumens Colour: Black Two CR123A Battery or One 18650 battery 4-hour working time(2.5-hour peak brightness) 131m(L)*33mm(D) Constructed of aircraft grade aluminum Type II hard anodized finish,highly durable Waterproof Toughened Ultra clear glass lens with AR coating Push-button tail cap switch