The Hevea Moon Ball activity toy is made from non-toxic pure natural rubber, ideal for playful puppies and small to medium sized dogs. The Moon Ball is designed with a hole which makes the chewing experience more comforting and enjoyable. You can tuck in treats to keep your dog entertained. The ball has an uneven surface which makes a whistling noise and makes it change direction when thrown. The natural rubber is strong, durable and long lasting. It is also non-toxic, free of phthalates, petroleum, PVC and heavy metals.