Ultrasonic Aroma Diffuser - black   The ultrasonic aroma diffuser works on the principle of ultrasonic waves, which ensure the evaporation of a mixture of water and essential oils. The result is a gentle cold steam that disperses around the room. You choose the scent of your choice by adding essential oils to evoke pleasant feelings. Without the addition of essential oil, the aroma diffuser can be used as an air humidifier. To evoke the right relaxing atmosphere, the diffuser is equipped with a pleasant LED backlight in seven colours.