Made from Ceramic Stone which absorbs moisture better than Sandstone. Absorb the condensation from iced beverages without going moldy, keep your car cup holder dry and clean. Suitable for both hot and cold drinks. The car coasters set is specially designed for car cup holder with one convenient notches on the side of coaster for easy removal. It never stick to the bottom of your bottles or cup then fall back onto you when you pick up your drink. Size: 2.5 inches in diameter