 We, once in a while, have to take a squeaker out of a dog, and that's not fun for your veterinarian or fun for the dog. So, again, they should be pretty much indestructible toys. Let's get into some specific examples. Doug, how about the very hard plastic bones that are sometimes advertised for strong chewers, like, for example, Nylabone? Some of them are so hard, I can't imagine them being safe for teeth.