Features a unique ball-within-a-ball design that will drive your dog bonkers;Perfect to keep your dog entertained as it rolls & wobbles erratically;Helps keep your dog occupied & mentally stimulated;Suitable for Dogs 40-80 lbs;8 Size perfect for large dogs;Made of hard plastic holds up to the toughest bite!;Ball inside a ball will keep your dog busy for hours;Rolls erractically and floats!