Knut Bø MURO 100 HTK is a 4-inch wall or ceiling exhaust fan with adjustable humidistat and timer, delivering an unloaded air volume of 90 m3/h. The humidistat starts the fan automatically when ambient humidity exceeds a user-set threshold, and the timer holds the fan on for a set interval after switching. Typical applications are bathrooms, toilets and small utility rooms requiring humidity-controlled ventilation.