The magician borrows a quarter (or other coin) and places it under a handkerchief. Next, he removes a gleaming brass box from his pocket.
Then the handkerchief is shaken out. The coin is gone. A spectator is invited to open the shiny brass box. Inside he finds another brass box, tightly closed. Inside the second box is found a third, and inside the third, a fourth, smaller box is discovered. Inside the final, smallest sealed brass box is discovered the missing coin - which can be marked for later identification if so desired.
Each set comes complete with four precision-machined nesting brass boxes, the appropriate "something" and complete instructions.