Water evaporates through the high-tech fabric of this humidifier, maintaining a constant level of humidity. Unlike many other humidifiers it is very easy to see when your Oasis needs refilling as the humidifier shrinks as water evaporates. Includes refilling syringe and a neodymium magnet system that allows you to install inside your case using either the included clip or sticky backed metal strip. Use of distilled water is recommended.