Obsidian Ultrasonic Aroma Diffuser A vase-like shape and marbled black and white swirls highlight the gentle movement of mist when the Obsidian Medium Diffuser is in use. The Obsidian Ultrasonic Aroma Diffuser has a few key features. * Diffuse a refreshing mist of water and essential oils for aromatherapy benefits and natural fragrance that can enhance your mood. * Features two mist modes for up to 8 hours of use. * 8 LED colours, an auto shut-off feature and 100 ml capacity. When using the Obsidian Ultrasonic Aroma Diffuser use 100% pure essential oils. Add up to 5 drops of essential oils per 100 ml of water, replace the decorative sleeve, switch the diffuser on and enjoy a spa-like aromatherapy experience in your own home.