Fill your space with the scents you love. Serene House's best-selling Corona Ultrasonic Diffuser runs up to 7-hour continuously or 14-hour intermittently. Customize your experience with the 60, 90, 120-minute timer and 7 LED lights. The 7 LED lights can rotate or fixed one color. To use, add water and the essential oil of your choice, turn it on, and let the cool mist refresh you.