A large (10" x 10") card with four spots is shown. A wave of the card and 2 spots vanish. Another wave of the card and the 2 spots return. After a bit of by-play the card is turned around, but now there are no spots on the other side! When the card is turned again there are 4 spots, each a different color. The card opens up to reveal an eye chart. A very nice item in new condition.