With this dehumidistat by Ranco you can control the humidity levels in a room automatically, making the room more comfortable as well as reducing the risk of mold and deterioration of your valuables. You can set this controller to turn on an exhaust fan or dehumidifier with a simple installation and greatly increase their effectiveness. In rooms with high moisture such as bathrooms this controller will keep your ventilation fan on until the damaging moisture is removed from the air. Make your home a healthier environment by connecting this controller to a dehumidifier or ventilation fan allowing it to turn the unit on until a comfortable atmosphere is created.No returns on this item.