Sporn Durable Marrow Chew Bones are the chewable nylon bones with "Jerky Flavour Down the Middle!" Perfect for strong chewers, nylon shavings act like a tooth brush and help remove tartar from the dog's teeth. Unlike traditional rawhide bones, this bone will last! Sporn has a size for every dog. If your dog is a power chewer, Sporn recommend choosing one size up.