The Vornado Mistic 4 Ultrasonic Humidifier boasts a clean look, cool mist and the convenience of a True Top-Fill design that allows you to fill the tank without opening the lid. Whole room humidification distributes up to 1.5 gallons of humidity per day (up to 400 sq. ft.), while included scent pads allow you to enjoy aromatherapy with your favorite essential oils. A 2-stage independent ambient light helps your ambiance, and simple touch controls let you switch between the 3 mist settings and Night Mode. The 4-liter tank, is wide open, making filling and cleaning easy.