This ball comes with holes on either side to stuff with treats to keep your dog stimulated and keep their cravings at bay. All Orbee-Tuff toys are made from a durable TPE material that is BPA, lead, and phthalate-free. Clean with warm water, mild soap and rinse. Not all sizes are suitable for all chewers and all sizes. Sizing: The Orbee-Tuff Tennis ball is 2.5" in diameter, has a classic look and is great for small dogs.