USB-C rear light with 20 super bright COB LEDs. Functions: Steady 100%-50%-25% - Flashing 100%-50%-25%. Integrated STOP function with light intensity change during braking. Press twice to change the function from "off" to "flashing". Long press to turn off. Rechargeable lithium-polymer battery (3.7V/400mAh). Charging time 2H and 30. Double attachment: rubber strap for the seat post or bracket to be fixed to the saddle rail.