Multiple layers of resin and sand* are used to create these beach coasters. The resin is poured onto ceramic tiles, and cork is glued to the bottom to protect your furniture surfaces. Coasters measure 4.25". This listing is for 1 coaster. Each coaster is one of a kind, so the coaster you receive will vary from the ones pictured, but will have blue tinted resin. *Please note we do not use sand from HawaiiÕs beaches, but a combination of aquarium substrate and play sand.