[SMART BRAKE SENSING ] - Automatically switches to maximum brightness to alert vehicles behind you when braking, improving your safety; You can use the metal mounting bracket to mount the smart bike tail light under the saddle [ 20 MOVING LIGHT MODES ] - The main light of brake sensing bicycle rear lights has 4 light modes: medium bright, low bright, diffuse flash, fast flash; The secondary light has 5 moving light modes, the combination is up to 20 light modes (you can refer to the video for the lighting effect) [ SMART ON/OFF FUNCTION ] - The bike lights are equipped with motion sensors, when keeping still for 30 seconds, the lights automatically go into standby to save power, and automatically light up when it senses vibration; Feel the wonders of smart bike lights [ BATTERY REMINDER ] - Bicycle taillight switch button is green when the battery is about 75~100%, orange when it is about 50~75%, red when it is about 25~50, red blinking when it is about 1~25%; So you can grasp the battery of the lights in real time, and recharge in time [EXTRA LONG BATTERY LIFE & WATERPROOF] - 600mAh battery powers your ride; Up to 28 hours of use after a full charge; IPX6 waterproof rating to withstand all weather conditions, suitable for any riding environment