Denew Bicycle light group (front and rear light groups), bicycle light LED, 2 light modes, USB rechargeable, waterproof, 400 lumens Waterproof and rechargeable : LED bicycle lights are waterproof. The headlight housing is made of high-quality metal and can withstand all adverse weather conditions. Use a laptop, wall mounted device, or power bank to easily charge your bicycle lights. Never waste money on batteries again, bid farewell to replacing batteries every week. [Continuous operation for 10 hours]: Equipped with a 2000 milliampere hour lithium-ion battery for advanced USB rechargeable bicycle lights. The front lights can be used after 4 hours of charging, up to 10 hours (5 hours in full light mode). After charging for 2 hours, the taillights can be used for up to 9 hours. Low power reminder: When the power of the bicycle lights is low, the button position will light up in red and remind you to charge. There are two modes of headlights: high brightness and medium brightness. When you are on the road but the indicator light is on, you can adjust the brightness of the bicycle light to 15 lux (the maximum brightness is 30 lux) to ensure a longer working time.