Back in stock! We've tracked down a few more of these pens. The successor to the famed 1950's yo-yo pencil, the Yo-Yo pen boasts a three quarter sized imperial glow in the dark yo-yo (about 1.75 inches in diameter) that has been internally weighted so it can play. The yo-yo snaps in and out of it's dock at the top of this ball point pen for easy but secure access. The write thing to have with you at all times.