Galileo, the world's strongest dog bone, is made of super-tough virgin nylon and lasts far longer than other chew products. It is so strong that you don't have to throw it away when the knuckles are chewed down. Discard it only when it is small enough for your dog to swallow whole. Galileo is safe to chew. The thin shavings that are raked off during chewing and swallowed pass through harmlessly. Galileo saves teeth by effective cleaning and vigorous gum massage and since Galileo is non-abrasive, there is no tooth wear.