JMT 12v Photosensitized Diode Relay Module Light Optical Module Photosensitive Sensor 12v Photosensitized Diode Relay Module Light Optical Module Photosensitive Sensor Light detection brightness detection, by potentiometer adjustable detection brightness valves, relays, to do various brightness detection switches, you can control the lights, automatic opening at night, automatically turns off during the day and supplies control and automation equipment in the car.