Functions: Function of humidification and dehumidificationHysteresis functionHumidity correctionDelay protectionFunction of Upper and Lower limitKey notes: RST: Press key RST to switch satrting up and power off, on the condition of power off, it can start up when press key RST, on the condition of starting up, it can power off when press and hold the key RST for three seconds. SET: Press key SET to enter settings of humidity control, and press key UP or Down to adjust. Press and hold key UP or Down for three seconds to enterthe fast adjust mode. Press key SET again to exit setting mode. Package Includes: 1 x Humidity controller WH80401 x Humidity controller sensor probe with cable1 x Temperature sensor probe with cableNOTE: For customers from Europe, Australia, New Zealand, most Asian Countries, South America and Africa, Use 220 V. The temperature sensor being used to calculate humidity more precise depending on the temperature inside of the house and it should be installed in the vicinity of the humidity probe.