Intelligent Induction: Built-in magnetic sensor- the warning light will start flashing for 110 seconds once the car door is opened, and then the light will turn off automatically Universal Design: Fit for any cars, SUV, truck; Wireless design, do not destroy the original car lines, only need to stick them at the door 3 Flashing Modes: 0-7 seconds- All LED rapid flashing; 7-60 seconds- Each LED sequential flashing; 60-110 seconds- Each LED slow swirl flashing Safety Driving: When the door is turned on, the red light flashes rapidly, warning the rear to the car, to avoid the dim light when the accident occurred and chase Long Lifespan: Powered by CR2032 button battery, low consumption and energy-saving, easy to replace by yourself; Waterproof cap and build in high-tech component sensor