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.Glow Ball - Simply hold under a light source for a few minutes and this rugged ball will glow for hours. No more losing Fido's favorite toy when playing fetch in the early morning or late evening darkness. This ball is safe and non-toxic and made of a synthetic rubber. No batteries required.