This Paw-lymorph D20 Dog Toy is a functional D20 – all numbers follow the standard placement for a 20-sided die, with the only exception being a "dog-treat opening" on the 1-face. The toy itself measures approximately 4" wide and is made out of quarter-inch thick, food-grade rubber. The D20 Dog Toy has been tested using seven different breeds of dogs, with a special emphasis on 'tough-chewers,' to ensure its durability and longevity. The material is dishwasher-safe (top-rack only), for easy cleaning between use!