Durable Fetch Toy Carefully choose the ball size to fit your launcher. Medium is the standard most common size. All balls fit Chuckit launchers Each ball stimulates a unique aspect of the chase! Pack of 3 All of the Chuckit! balls are specifically designed for the most demanding use by a growing population of fetch enthusiasts. Each ball is compatible with the Chuckit! launchers, so that you do not have to bend down and pick up a slobbery ball. Ultra Ball - Is designed for the most demanding use. This is no ordinary ball! It bounces higher, flies farther, and floats higher than most other balls. This is our most popular Chuckit! ball.