Dri-Mark Smart Money Counterfeit Bill Detector Pen For Use W/U.S. Currency, 3

Dri-Mark Smart Money Counterfeit Bill Detector Pen For Use W/U.S. Currency, 3Mark on a non-printed area of the bill, if the mark stays amber the bill is valid. If the mark turns dark brown or black, it should be considered suspect of being counterfeit. Effective on US bills printed 1959 and later.