Each set is 2 car coasters. Car coasters are neoprene and have anti-skid rubber bottoms. Car coasters are about 2.75" in diameter which makes them almost universal. They may not fit some car cup holders, but fit most. These coasters can be used for your table, desk, or wherever you need one as well! The added notch allows the coaster to easily be removed from car cup holders when it needs to be cleaned. Perfect for keeping your car cup holders or other surfaces clean and dry. These are absorbent and can easily be washed. When the car coasters get dirty, just add a drop of soap, rub with warm water, and let air dry.