This classic clockwork ring simulates an electric shock by vibrating during a handshake. Invented by the great S. S. Adams in the late 1920s, the Hand Buzzer is as good an ice-breaker today as when it was invented. It’s still not a very good ice-breaker.

These are from a company that has manufactured and traded jokes since 1924. They come packaged with fantastic artwork as you would expect from Funny Man jokes.
 
Manufacturer's safety information: Not suitable for children under 3 years. Choking hazard due to small parts.