THEBEN LU 112 is a twilight switch that can be used to automatically control lighting based on the ambient light level. It can be used for a variety of applications, such as street lighting, shop window lighting, and factory lighting. The device has a built-in light sensor that detects the ambient light level and turns the lights on when it gets dark and turns them off when it gets light. The LU 112 also has a built-in timer that can be used to set the time at which the lights turn on and off. This can be useful for ensuring that the lights are always on when they are needed, even if the ambient light level is not low enough to trigger the light sensor.