This is the aroma diffuser that uses ultrasonic waves to quietly freshen a room and release pleasant scents without heat, flames, or moisture. Unlike many aromatherapy devices that emit a scalding hot steam or rely on dangerous candles with messy wax, this relaxing device uses inaudible high frequency waves to produce a safe, cool mist. The calming diffuser is quieter than a whisper and is easily operated by filling the bowl with water and a few drops of your favorite essential oil (not included). With a minimalist design that blends in with any décor, the diffuser runs in 10-minute intervals every 24 hours (or four continuous hours) to keep your home fresh-smelling without needing to be refilled. With an automatic shut-off. Plugs into AC. Black. 5" H x 3 1/2" Diam. (12 oz.)