Unlike the regular Flavorit™, the Flavorit Flex™ is a flexible bone that is engineered with moderate or gentle chewers in mind. Tiny flavor cells are molded into both sides of the Flavorit Flex™ bone so you can fill it with peanut butter, cheese, cream cheese, or any other spreadable treat your dog prefers. The tiny flavor cells hold just enough spread to entice your dog to chew, but not too much that they're getting so many calories. You can even add a different spread on each side to up the flavors! No mess because it’s concave design. Once your doggie is done chewing, simply clean the bone with a small brush. Now it's ready to be re-charged with your dog’s favorite spread again. Even though it works great with all kinds of spreads, dogs love it on its own too! The Flavorit Flex™ Peanut Butter bone is infused with human-grade peanut butter flavoring, allergen free!It is generously flavored to the bone; you can literally smell the goodness of peanut butter even inside the packaging. The result is a delicious smelling and drool-worthy bone your dog will love even without a spread! Giving your dog non-edible bones also massages their gums and provides scraping action on their teeth, much like a dental hygienist descaling the plaque from human teeth. This bone is NOT recommended for aggressive or power chewers. If your dog is a strong chewer, try the Flavorit™ Peanut Butter instead.