The snack ball dog toy is made from safe and extremely durable solid rubber how does it work just fill the snack ball with tasty treats your pet will try to get the treats out of the ball by rolling it around and playing with it however treats will only be released in small doses due to the ingenious snack labyrinth design which keeps the treats moving around through the opposite openings until your dog can finally get its paws on the reward diameter of hole for filling 25cm the snack