The RHC Relative Humidity Controller is our most recent development in total humidity control. It is switchable between humidify and dehumidify. The RHC has a built- in onboard sensor which is accurate within +/- 5% with a set differential of 5%. Perfect for plant zone environments, reptile habitats, or just about any application requiring accurate response and control. Plug your humidity equipment into the 120 volt 3 prong piggy-back cord.