SpaRoom's DuoMist Essential Oil Ultrasonic Diffuser features a sleek and modern shape and includes two different light modes to customize your aromatherapy experience. The diffuser includes an automatic safety shut off for peace of mind and will provide continuous mist for up 5 hours on the small mist setting, 3 hours on the medium setting and up to 2 hours on the large mist setting. The ultrasonic diffuser is perfect for medium sized room up to 200 sq. ft. of space and it has a water capacity of 240 ml (120 ml per each tank). Simply add a few drops of our 100% pure essential oils for easy setup to enjoy instant therapeutic benefits and a wonderful, natural aroma through your space.