The Eos? 2 Digital Humidity Controller makes dialing in your room's environment a breeze. It can be used to activate a device to increase humidity in your room or decrease the humidity in your room. The Eos? 2 utilizes a high-quality humidity sensor as well as a photocell for day and night control. Settings are easily programmed with the knob that doubles as a button to change settings. A slide switch controls whether the controller is running in Day, Night or 24 hr mode. 10 Amps/ 120 V/ 60 Hz.