The Orbee-tuff compound is really tough with an interesting "feel" that is difficult to describe. Orbee toys are made of an injection molded "thermo plastic elastimer". The molding process makes them hollow with holes at the ends and gives them a 1/2 inch thick membrane-like surface. This process creates an incredibly durable and safe material that stands up to sharp teeth and rough play. It's flexible, durable, grippy, bouncy and buoyant, has a peppermint scent and rinses clean. Being hollow, Orbee toys can be stuffed with treats, peanut butter or whatever your dog has a love for. To add an additional option to the mix, all of these toys can be safely chilled or frozen for a cool treat on a hot day! Orbee toys are also non-toxic & recyclable, which makes them great for the environment too!