The Simply Silent CV4SR Humidistat / Timer is a continuously running (dMEV) extract fan. It delivers a constant volume of extracted air to eliminate humidity, condensation and mould growth in bathrooms, shower rooms, kitchens and toilets. _selectable bathroom and kitchen airflows, with 3 speed options for each _Features Xpelair's intelligent adaptiflow sensing technology which delivers constant volume performance due to a unique sensor housed within the duct. The sensor calculates and records the airflow of the fan and adapts the fan speed intuitively in accordance with changes in airflow to maintain the required fan speed. _Supplied with both circular and square baffles for preferred style finish _Ghost Airmovement technology for near silent running _IPX4 rated and a 5-year UK guarantee