The ball is made of high quality rubber, non-toxic and environmentally friendly, safe for your dog’s health. It is strong and durable, well resistant to bites. The wheels can turn 360°and help dogs clean their teeth when they bite the ball. The little nubs on the ball can also help to clean the teeth. You can put the kibble in the ball to attract the dog’s attention and the kibble is a bit hard to reach and allows the dog to bite longer and brush the teeth. Bringing fun and exercise to the dog’s life, the chew toy helps to develop the dog’s intelligence and health. Note:Natural rubber has a typical smell, it will disappear naturally after a few days.Don’t worry.