Price: 1 Euro in 2004.
Quite nice design with an internal switch controlling the LED. When spinned, a ball moves outwards due to the centrifugal force and triggers the switch.
Amazing that someone can produce a thing like this for one Euro, including the two small batteries.
Price: 4 Euro in 2004.
"Develops grip, wrist and forearm improves your grip for golf, tennis, raquetball, any sports. Spin like a dynamo and humms like a bee." That is the promise, and note; no battery required!
Yes, you can get it spinning following the operating instructions but I think you get more exersice by a handshake with someone.