Mighty Mutts Rubber S Bone. The Mighty Mutts Tough Dog Toy Rubber S Bone is just the thing for excitable dogs with sharp teeth, saving you the hassle of replacing your dog's toys after only a few days of intense play and wild chew attacks. This red S bone is made from hard-wearing thermoplastic rubber (TPR) is guaranteed to last at least 3 years. The S Bone also floats so can be used for water play. Size: 19cm Diameter Approx, Dogs 27-40kgs