ABOUT INKBIRD Established in 2010, Inkbird is specialized in manufacturing and selling home automation products like temperature controllers, humidity controller, hygrometer and thermometer, etc. ?With more than 10 years of home intelligent control product design and service experience, the company has become a high-tech enterprise that providing R&D, manufacturing, marketing, and operation service. Main Features: Multifunction: humidification dehumidification Humidity calibration Hysteresis function Humidity correction Delay protection Alarm when sensor error or humidity exceeds limit Use Humirel Humidity sensor HTG3535CH The probe is WATERPROOF that can prevent the liquefaction of gases such as mist and water vapor. Specification: Power Input: 100 ~240VAC, 50Hz/60Hz Power Output: Max. 10A, 100V ~240V AC Humidity Measuring Range : 5%-99.99%RH Humidity Control Range : 5%-99%RH Resolution: 1%RH Accuracy: ±3%RH Input Power Cable Length: 1.5m (5ft) Output Power Cable Length: 30cm (1ft) Dimension: Body: 140x68x33mm (5.5x2.7x1.3inch) Socket: 85x42x24mm(3.3x1.7x1inch) Ambient Temperature : -30~ 75 ° C / -22~ 167 ° F Storage: Temperature : -30~ 75 ° C / -22~ 167 ° F ; Humidity 20~85% (No Condensate)If you want to maintain the humidity from 47% to 55% Set "HS" (Traget Humdity) as 50.Switch on the powerPress the "SET" button for 3 seconds to "HS" humidity settingPress the up or down button to adjust the humidity to 50%Set "HD" (Humidification Differential Value) as 3.Press the "SET" button to select "HD"Press the up and down button to adjust the humidity to 3%Set "DD" (Dehumidification Differential Value) as 5.Press the "SET" button to select "DD"Press the up and down button to adjust the humidity to 5%