Smart Bike Tail Light - Auto On/Off, High Lumen LED, USB Rechargeable, Waterproof Safety Light

High lumen COB LED for maximum visibility and safety during day or night rides. Auto on/off functionality and brake light mode for improved road safety. Built-in 115dB alarm with motion and vibration detection to deter theft. 3-level brightness and 4 lighting modes for customizable lighting options. USB-C rechargeable battery with 40-hour battery life and fast 3-hour charging.