The classic nerve stimulator is a rolling pinwheel of sharp little points. The points are not sharp enough to puncture the skin unless excessive pressure is applied. This item is a wonderful addition to a violet wand it can create a very intense stimulus when used with the wand. In fact, it goes so well the the violet wand that a Wartenburg Wheel is included in our deluxe wand kit. Wartenburg Wheel comes in sheath for safe storage.