WHEEKY Treat Ball Adjustable Opening Puzzle Toy for Medium Dogs (20 to 50 lbs) - 11 cm/4.3-inch Diameter - Blue Great boredom buster for medium dogs (20-50 pounds); interactive IQ treat ball and puzzle toy provides fun mental and physical workout Adjustable opening for different size treats; open wide for learning, then reduce size for extended play Also great as a slow feeder for pets that eat too fast Ball size is 4.3 inches in diameter (11 cm); perfect for medium breed dogs such as cocker spaniel, spring spaniel, Australian shepherd, pug, beagle, Border collie, sheltie, and more Not a chew toy, but an interactive treat ball designed to be pushed and rolled by treat-motivated pets