Advantage:[Material] -Made of slate material, reliable and solid, lightweight and compact, not easy to break, bend, or fade, with a raw edge to offer visual attraction. You can also write on them with chalk, painting with acrylic paints, art mosaics or other.[Protect Table Safe] - These slate coasters protect the tabletops surface from oil, heat, and water spills. The non-slip design ensures that your mug or drinking glass stays in place, preventing any scratches or damage to your furniture.[Wide Application] - Great for use in your home, office, or cafe and make an impression on your guests. Suitable for cocktail glasses, coffee mugs, mason jars, tumblers, flasks.