This is a checkmark stamper part for Double Cross. It allows you to secretly stamp a checkmark on the spectator's hand.
The routine goes like this, "You've been such a great audience - I'm going to pay YOU!" You draw something on your hand and then show them. . . it's a checkmark. "Do you take checks?" (yuk yuk).
Now close your hand into a fist as you say "What makes this one special is . . . it bounces." Now open your hand to show the checkmark has vanished ... as the spectator opens their fist - its magically jumped to their hand. Checkmate!
The checkmark it produces is made to look exactly like it was drawn by hand. This is the checkmark stamper only - you must already own the Double Cross pen in order to use this gimmick. The size of the checkmark is approximately .28" x .28".