Each Invincibles Mini is stuffed with one large Invincibles Squeaker helping your dog chew longer because all Invincibles squeakers Keep Squeaking If Punctured and have no fluff/stuffing. That means more fun, and less mess. An anterior layer of super durable material creates a powerful protective shield. Heavy duty binding adds an extra layer of strength that’s built to stand up to fun and games with even the toughest chewers!