Holds a Variety of Treats and Kibble. Use Starmark's Lock & Block Treats in each end.  Increase the challenge by adding smaller treats inside.  Lock & Block Treats made in USA. Made with Virtually Indestructible Material. Great for powerful chewers.  Free of latex, vinyl, and phthalates. Provides Hours of Challenging Play. Treat Ball system encourages play which helps reduce anxiety and boredom behaviors. Nubby surface helps clean teeth and gums.  Dishwasher safe. Made in USA.