This extremely durable natural rubber ball can stand up to some serious chewing its ideal for dogs who love running after balls carrying them around and chewing them non stop the hole in the middle of the kong extreme ball can also be filled with treats making it even more attractive and exciting for your dog manufacturers sizing recommendations size s for dog up to approx 16kg diameter approx 6cm size ml for dogs up to approx 30kg diameter approx 75cm please note no toy is in