This light sensor module will interface with the home automation system to turn an output device on or off. It has an adjustable light setting to detect the desired ambient light trigger. You can interface this with a 240v mains controller to turn a light on at dusk or a 12v controller to open the curtains at the first sign of light. Features wireless range 100m line of sight wireless frequency 433mhz battery used for main product size shape 9v battery quantity 1.0pc effective range 100.0m