Sporn Durable Marrow™ Chew Bones are the chewable nylon bones with "Jerky & peanut butter flavor Down the Middle! Perfect for strong chewers, nylon shavings act like a toothbrush and help remove tartar from the dog's teeth. Unlike traditional rawhide bones, this bone will last! Marrow™ Chew Bones are available in 5 sizes to suit every size dog.