Turtleback Sand Coaster Drink Cup Holder Beach Accessory - Pack of 4 (Purple) Set of Four Turtleback beach drink holders. Holder opening 3" diameter x 1.75" deep. Small, portable and stackable. Simpy push down into the sand, dirt or grass to provide a clean, stable holder for your drink, phone, suntan lotion, keys, etc. Turtlebacks are made in the U.S.A of recycled material. A must have for your next beach, lake or camping trip!