Strauss Bicycle Solar Tail Light and Bicycle Zoom LED Torch with Mount Holder Solar powered the solar bike light full charged needs 4 hours(sunlight) and work for 6-8 hours Solar power, energy saving, environment friendly with 3 modes of light, slow flash, quick flash, steady light High-quality the torch is made of solid aluminium and reflector by rugged abs plastic You can use 3 x aaa battery or 18650 battery for the flashlight Three light modes free to switch this bike light has three light modes-full brightness/half brightness/flashing.2.5 hours in strong light/8 hours in weak light