The Everlasting Bento Ball can be filled with food, Every Flavor Treats, or any snack your dog enjoys and then capped with one Everlasting Treat. Everlasting Treats can be inserted upside down or into the center cavity for more challenging play. Fit two Everlasting Bento Balls together with the Everlocking Treats. Dental dimples on the outside help keep teeth clean. Dishwasher safe in the top rack for easy clean up. Completely free of latex, vinyl, and phthalates. Medium (3.5″ diameter) recommended for dogs under 40 pounds If your dog is a strong chewer, we recommend selecting the larger size. Provides hours of challenging play Free of latex, vinyl and phthalates.