Whole House Humidifier with Essential Oil Tray This large humidifier has a 4.2 gallons (16 liter) water capacity and can produce mist output up to 2000mL/h, covering an area up to 2000 sq.ft. The included essential oil tray allows you to add your favorite scents to the mist. Free Pipe adjustable freely for your multiple use like plant and vegetable growing and moisturizing. Note: At first time to use, please take out the user's guide and all the accessories from the bottom of the tank. Smart Humidifier with Customized Humidity Settings You can customize the humidity level from 40% to 90%. When the humidity reaches the set level, the mist will be suspended.