One of the lightest, brightest, most comfortable head-lamps available today. Features High and Low lighting modes and a runtime up to 12 hours. Powered by two 1.5V "AAA" cells (included). .5 watt high-flux, 100,000 hour life LED. Impact-resistant, drop-tested housing. O-Ring sealed construction. Waterproof to 1 meter for 1 hour.