The Kong, Medium Stuff-A-Ball is made of Durable Rubber and measures 3 3/4 inches high, 3 inches across, and 3 3/4 inches deep. It has 16 Vertically Grooved Treat Slots w/Treat Grip Ridges plus a Hollowed Core giving you an outstanding Treat/Dental Work Out System. This Ball has the highest flexibility of any canine treat device on the market and that equals high tactile enjoyment for your pet.