PIRA Classification: 1N30.62
Description: Four discs (1 5/8", 3 1/8", 5", and 8") are placed on top of each other such that they stand vertically. The four discs are also confined to the vertical plane. Raising and releasing two discs will cause the smallest disc to bounce a few inches. Raising three will cause the smallest disc to bounce out of the apparatus a few inches. Raising and releasing all four will cause the smallest disc to hit the ceiling.
Special Instructions: None
Condition: OK
Setup time: 1 minute
Safety Issues: Keep your eye on the disc.