Ultrasonic diffusers

An ultrasonic diffuser breaks water and oil into a cool mist, so nothing is heated and the scent stays true. Ours are built in matte ceramic and stone rather than glossy plastic, hold 200 to 500 ml, run for up to eight hours and shut off on their own when the tank empties. Each one ships with a 10 ml bottle of oil. Prices run from $49 to $79.