Meet the Tennis Tumble, the ultimate interactive puzzle toy for dogs development. Our Tennis Tumble promotes challenging, independent play for medium to large dogs. Featuring a hollow tube shape and a trapped tennis ball inside, test your pups smarts and see how quickly they can free the tennis ball.Recommended for medium and large dogs.Materials:Tennis Tumble: Natural RubberTennis Balls: Natural rubber core, pet-safe poly felt exteriorProduct Dimensions & Specs:Length: 3.86″Width A: 2.56″Width B: 2.48″Ball Diameter: 2.36″ (about the same size as a regulation-sized tennis ball).