Thirstystone Walnut Wood Coaster Holder. Coaster Holder is constructed of sturdy solid Walnut Wood. Coaster Holder can hold round or square coasters. Holds Coasters approximately 4? to 4.25?. Will Hold 4 Coasters at a time. Coaster Holder is an attractive way to store your household Coasters when they are not in use. Holder measures 5.13? x 5.13? x 2.25?.