Forum Novelties FBA_9301790 Twicebooked Practical Joke Prank Bundle Pen and One Pack Shocking Chewing Gum, Black Bundle includes one shocking prank pen and one pack of shocking chewing gum. Gum is 3.5 inches in length. Shock pen produces safe 50-70 volt shock, non-replaceable battery included. Great party gift or party entertainment! Best as a short term gag, not as a toy to be played with long term. For ages 14 and up.