Environmental Protection Materials Made of high quality absorbent ceramic and anti wear cork, low carbon, non-toxic, waterproof and moisture-proof. Absorbent Ceramic To Keep Your Furniture Dry Coasters upper layer is absorbent ceramic, which will keep your furniture dry. Non-Slip Cork Bottom A non-slip cork mat is placed on the bottom of each coaster. The coaster is firmly attached to the table and prevents the furniture from being scratched. More Details The bottom edge of the coaster is polished more rounded, which further prevents the table from being scratched and avoids scratching the child's hand. Little Tips If coffee or dark drink splashed on the ceramic coaster, we recommend you to wash the coaster with water immediately.