Nylabone Galileo Chews are the strongest dog bone for powerful chewers. Nylabone adapted the science of "strength of materials" discovered by Italian astronmer and physicist Galileo Galilei (1564-1642). Nylacone created Nylabone Galileo Chews in different sizes and shape, and they are all molded from extra-tough nylon and annealed for greater strength that last longer than most other bones.