kinjalgp said:That pen you are talking about is a mechanical one which uses the same concept as household piezo gas lighters do. Whenever you press the trigger, a metal bar is truck heavily onto a piezo material which generates a high voltage spark and its really painful to touch it.
Even gas ligther can be turned into a schocking pen. Do it at your own risk. The person you are shocking might not leave any one-piece bone in your body.