Fans offered by us feature high air exchange efficiency, quiet operation, low energy consumption as well as vast selection of optional equipment. Our extractors perfectly supplement gravitational ventilation, ensuring efficient air exchange in each room. Timer - The device is switched off with a regulated delay (from 3 to 30 minutes) following the light switch off. Humidity Sensor - the exhaust fans permanently supplied with power are switched on when humidity in a room is detected. They are switched off with a regulated delay from 3 to 30 minutes. The hygrostat regulation is supported by a diode (green) placed near a potentiometer that defines sensitivity of the humidity detector.