Oyster Gray Shell Foam Coaster Set of 4. Square Artwork Foam Coaster set of four coasters. Each measuring 3 1/2 inches by 3 1/2 inches. Permanently dyed with full color artwork and fade resistant. Great to keep water from your beverage off your table and add a bit of flair to a gathering. Match with one of the insulated coolers or huggers for a nice gift pack. Wash the coaster in the top of your dishwasher, take out and lay flat to dry. Design will not come off. Made from the same material that we use for our mouse pads. Material is heat resistant. Perfect for cold or hot drinks. Coffee or tea. This Coaster set is from Martin's Seafood category of products.