Dehumidistat Wall Control Switch in WhiteThe DH100W white dehumidistat is a control switch which operates a connected fan based on the relative humidity it senses in a room. A user can set the desired humidity level and the dehumidistat control will activate or switch on the fan to ventilate the room once it detects higher humidity. The fan will remain on until the desired humidity level is reached, at which point the humidistat will shut the fan off. Variable setting from 20% to 80%