Natural air care Stone uses all-natural oils to safely scent your space. That means no harsh chemicals or other toxic ingredients. Functional art Stone’s high-quality matte ceramic cover looks like a piece of pottery in your home. Flexible timing Stone has two time settings (4-hour continuous and 8-hour intermittent) to scent your space on your schedule. Safety feature Stone automatically shuts off when either the time setting is done or the water runs out. Ambient light Stone has an optional LED light that gives off a soft glow. Diffusing capacity Stone scents rooms of up to 500 square-feet, making it perfect for bedrooms and living rooms.