Each cover is made of fine porcelain ceramic, which is commonly used for works of art, useful dishes, and decorative and durable tile throughout the world. Artisans fire each molded piece of white clay twice to achieve the translucence of pure white porcelain as well as the desired shine and hardness. It is harder, denser, and less porous than regular ceramic, making it more scratch-, chip-, and stain-resistant and better able to hold up against heat and UV rays. Offering up to four hours of diffusion with a choice of three automatic timers, its translucent glow can set the mood to create your serene safe haven. Directions: Fill the reservoir with water and add 5–10 drops of essential oil. Select diffusion and light modes and enjoy. Features & Benefits: Crafted porcelain ceramic cover design made from natural materials High diffusion mode runs up to four hours Three timer options for automatic shutoff after one, two, or three hours LED light gives a translucent glow and dimmer options that can run independent of diffuser function Compact, space-saving size that fits easily on tabletops, in bathrooms, and in offices Essential oil diffusion coverage for medium-sized rooms of up to 375 square feet. Listing is for diffuser only. No oils are included.