Same rubber featured in our Puppy Kong toys, but in a ball shape for amazing fun. Ideal for playing fetch or simply chewing fun. Hollow center can be filled with Kong Stuff-N-Paste Easy Treat, or even peanut butter, cheese, hot dog chunks, treat biscuits, kibble, or any other foods your dog is crazy about. You can also fill with chicken, beef, or turkey broth and freeze. Makes your dog work for the treats, keeping him busy while you are at work. Unlike cheaper imitations, these toys have holes at both ends to keep a dog's tongue from getting stuck.