The toy itself is a functional D20, all numbers follow the standard placement for a 20-sided die, with the only exception being the treat-opening on the ‘1-face.’ The toy itself is about 4″ wide and made out of quarter-inch thick, food-grade rubber. We’ve also tested our toy using seven different breeds of dogs, and placed a special emphasis on tough-chewers, to ensure it’s durability and longevity.