6 Light Modes and Sensor Brake LightOur colorful bike tail light has red and blue alternating flashing mode, green flashing mode, red light always on mode, colorful breathing flashing mode, red light slow flashing mode, red light fast flashing mode, you can switch your preferred mode with one click. When you brake to slow down, the tail light will automatically sense 3 times brighter red light, as a warning light to remind the car behind to keep a safe distance, let you ride more safely. 2 Types of Bracket MountingRubber band bracket mounting method, adjustable length silicone band, compatible with various sizes of seatposts; Seatpost bracket, can be hooked to the two metal rails under the seatpost, suitable for all types of bikes, don't worry about mismatch with your bike. No wiring is required for installation, it only takes a few minutes to install, it is very solid after installation and will not come off easily during riding. Up to 50,000 hours service life Bicycle tail light adopts one-piece sealed waterproof design, 10pcs LED bright light beads, IPX4 waterproof, ABS shell, anti-drop and wear-resistant, beautiful and cool appearance, can withstand all kinds of weather conditions, suitable for any cycling environment. Indicator Light Shows the Power LevelThe bike tail light has a built in 500 mAh battery, which can be used for 40 hours. Can be easily charged by computer, charger or mobile power using charging cable. When you turn on the bike tail light, the small light is green (100%-70% power), the small light is blue (70%-40% power), the small light is red (40%-10% power); when charging, the red light breathes and flashes, and when the red light doesn't flash, it's fully charged.