This Skull Coaster Set features natural travertine stone construction. Absorbent stoneware helps to protect furniture from drips and condensation. Durable cork backing helps to keep your coaster in place along with protecting your furniture from scratches. Set of 4 coasters. Each coaster measures 4"x4". Made from natural travertine stone. Wipe clean. Imported. Due to the unique nature of natural stone, coasters may feature slight variations in texture and finish.