Have three times the fun with three different types of balls! The Whistler makes a great whistling sound in flight, Max Glow Ball glows in the dark (after exposed to a bright light source for at least 3 minutes), the Rebounce Ball contains recycled natural rubber for a feel-good bounce! These balls will fit in the Chuckit Jr! and the Chuckit! Pocket Ball Launcher. For supervised play only.