Features: brand new and high quality Model Number: Photoresistor Relay Module. Use: Adopts photoresistor induction light intensity, built-in relay, direct control of the load. Potentiometer sensitivity adjustment: With a potentiometer sensitivity adjustment, by adjusting the potentiometer, set the start relay valve value, when the light on the threshold, relay module pull-in, dark at the threshold, the relay release, so pick up normally open with the public is the control of the switch during the day, pick up normally closed with the public is to control the switch in the evening. Easy to install: Equipped with four M3 fixed bolt hole, convenient installation. Application: Can do all kinds of luminance detection switch, can control all kinds of lamps, automatically open in the evening, automatically go out during the day and the car supplies control and automation equipment and more. Specifications: Working voltage: 5V/12V/24V(optional) Size: 53x31mm Color: blue Material: electric components Package Includes: 1 x Photoresistor Relay Module note: 1. Please allowed 1-3mm differences due to manual measurement, thank you for your understanding! 2. Due to the difference between different monitors, please understand that the picture may not reflect the actual color of the item.