The Leviton Decora Humidity Sensor and Fan Control Switch detects excess humidity and automatically activates an exhaust or ventilation fan-helping reduce condensation and create a more comfortable environment. Its advanced digital sensing technology continuously monitors and manages moisture levels in areas prone to humidity, such as bathrooms, basements, laundry rooms, and spas. Replaces a standard switch and works with most bathroom or ventilation fans, including fan/light combinations. Shallow, compact design fits easily into standard wall boxes. Customizable settings let you adjust sensitivity, humidity level, and time-out duration.