4 Light ModesThe tail light can one touch switch into four different light modes depending on your demand: Include full brightness, half brightness, fast flashing and slow flashing.USB Rechargeable Polymer BatteryThe built-in 330mAh polymer battery can be used for more than 12 hours after being fully charged. They can be recharged with any device featuring USB ports. Absolutely the best USB bike lights for cycling enthusiasts!Waterproof & Light WeightThe rear light is made of IPX5 waterproof material, meanwhile, the USB charging port is also made of the silicone material, which has the strong anti-seepage ability, can well protect the interior of the lamp, and can extend the service life of the lamp. In addition, it weighs only 60g, can be easily installed on various equipmentEasy to InstallAdvanced and flexible silicone mounting straps provide great safety, holding the USB-rechargeable bike light set tightly enough to prevent falling off even on bumpy roads. Loosen and fasten them easily without any tools required. Fits All Bicycles, Mountain, Road.