The odd scientific principle discovered by Harris in 1980 makes an amazing coin transposition possible!
Two coins are displayed. One is marked with a large cross with a permanent marker and a spectator confirms that the cross will not rub off the coin. In full view, the marked coin and the plain coin transpose through the back of a spectator's own hand.

Fully examinable, easy to do. The scientific principle makes it all work.

examinable
use any currency
easy to perform
carry it everywhere