JW Pet's Crackle Heads Ball Medium is natural rubber ball covered with Hol-ee styled cutouts that expose the Crackle Heads Technology inside! Our patent pending Bottle Ball is placed inside the natural rubber cage to provide the crackle sound & feel that dogs love. The tough outer rubber molds around the bottle ball providing a protective layer that will hold up to rugged play. The Bottle Ball has no cap or sharp rings that can harm soft mouth areas. Crunchy & safe fun that dogs love wrapped into a classic functional shape! Suitable for Medium Breeds.