Urban Prime's waterproof rear bicycle light automatically detects vehicle braking, warning pedestrians and approaching vehicles to slow down. The 7 lighting modes allow you to be more visible at any time of day. Recharge it easily and quickly via USB cable, providing autonomy for up to 36 hours. The innovative driving status detection helps to save the lights' battery power, automatically switching off if you stop for more than 60 seconds and switching back on again independently once you start.