Surfing Sports LED Bike Lights - New Square Model Bicycle Headlight With 6400mAh Battery - High Quality Powerful CREE XML T6 1,200 Lumen Light - Rechargeable, Waterproof Battery Super bright high-power light/headlight.Ultra wide voltage input range:5.0V-24V.Constant power circuit design which ensures the brightness will not be affected by the changing of the power voltage. Intelligent circuit control and flexible mode alter.Three modes/five modes dimming memory circuit. Waterproof design,with noctilucent seal that flow after ligt is turned off. Aluminum alloy housing,anodized anti-abrasive finish. 4*18650 6400mAh Li-ion battery pack,wit up to approximately 3-1/2hours on high,up to 6 hours runtime on medium.