The Wartenberg wheel is a rotating wheel studded with sharp pins attached to a handle. It was originally invented by Dr. Robert Wartenberg and was used to test nerves and skin sensitivity. Today, however, it is very rarely used in medical settings, and has become more of a sex toy. The prickly wheel on this device can be rolled or dragged across the skin to create a number of different sensations, from tickling to prickly. It is most often used during sensation play.