IMPROVED ARROW TURN SIGNAL: Bike taillight with new arrow taillight design, cool stylish, 5 modes with USB charging, brake red light to keep you safe in the shade at night. (To note: This tail light is not recommended f daytime use) Remote Control Bike Tail Light: The bicycle taillight is remote controlled, the remote is fixed on the hlebar, which can control the bicycle taillight at any time. (To note: The maximum control distance of the remote control (without obstacle): 3-4 meters, if there is any problem with the remote, please contact us f a replacement) IPX5 Waterproof Rear Bike Light: The bicycle turn signal is IPX5 waterproof it is free to ride in rainy days. (To note: Please do not use this bike taillight in heavy rain) Wide application of bike taillights: Bike brake lights with high quality rubber bs are suitable f most styles of bikes. (To note: Not compatible with bicycle seat tubes with a diameter greater than 4.5 cm) Large capacity battery: The bicycle taillight battery is 800mAh, USB direct charging, 2 hours full charge, can reach 5.5-12 hours battery life.