The unique shape fits in your dog's mouth. Patented dental ridges help clean hard-to-reach back teeth. Made of safe, flexible, durable natural rubber. Fill with Kong Stuff'n Paste for an extra treat. Kong dog toys can be stuffed with your dog's favorite treats, dog biscuits, peanut butter, cheese, etc. for hours of exercise and chewing fun. While your dog tires to crunch up and lick out the "hidden treat," you are teaching him that chewing on a Kong is better than on the furniture. Recommended by Veterinarians, Trainers, Dog Professionals and Satisfied Customers Worldwide! Kong Toys Clean Teeth and Condition the Gums!