KONG Extreme is the most durable version of the original Kong. The ultra-strong, black rubber compound is recommended for power chewers and tenacious chewers. It is considered the World's Best Dog Toy for its legendary strength, quality and performance. KONGs are widely used for therapy and prevention of boredom, separation anxiety and other behavioral issues. Their unpredictable bounce lures most dogs into a game of chase, catch and chew. The hollow core of the KONG will allow you to stuff it with treats and food to entice play.