Constructed of aluminum alloy, LED 3 x CREE lights, and stretchy elastic head band size to fit all. Light weight, you wona€TMt even notice the weight of the headlamp. Explore anytime, any weather condition. This headlamp is water resistant, so exploring in the rain is possible. This lamp has 4 modes; 1 click middle light only on, 2 clicks outer two lights on only, 3 clicks all lights on, 4 clicks strobe. Powered by 2pcs rechargeable 18650 battery (included), it can also work with just one battery