Purchased from MUJI several years ago. Stored by a private individual, so recommended for those who don't mind. There is some slight deposit of inorganic substances and aroma pigments from water on the inner container. This ultrasonic humidifier can be used with your favorite essential oils. It's a simple, ultrasonic, tabletop mini humidifier compatible with aroma oils. The understated color makes it perfect for gifts. Small and convenient for combating dryness, it won't get in the way in any situation, such as on a desktop or in a bedroom. Please use essential oils that are 100% natural. Aroma oils may contain alcohol, which can cause malfunctions.