This module can be used for light detection, brightness detection, with power indicator light (red) and relay indicator (blue), and with four M3 screw mounting holes, which is convenient to install, the board can adjust the sensitivity of the potentiometer, with relay, to do a variety of brightness detection and control switch, can be used in the street for example at night, during the day to open automatically, automatically extinguished, and other automation equipment. Features: With anti-reverse function, reverse the power supply will not damage the module The light threshold can be adjusted by Potentiometer to set the relay start Module output terminal has three ports RED LED ON: Indicate the Power ON BLUE LED ON: Relay is working Relay Pinouts Normally open ( NO ) Common terminal ( COM ) Normally closed ( NC ) Package Includes: 1 x XH-M131 DC 5V Light Control Switch Photoresistor Relay Module Category: Relay