Chuck It Fetch Medley BallsChuckit! Medium Fetch Ball is the perfect toy for playing dynamic games of fetch with your dog. This small, bouncy ball provides a uniquely fun experience to your dog. Each ball contains a small hole and is hollow to allow for the insertion of treats or peanut butter. One ball, The Whistler, is also uniquely designed to produce sounds when thrown while another, The Max Glow, glows in the dark. Each ball is made from a flexible material that makes it