Dri-Mark Smart Money Counterfeit Bill Detector Pen for Use w/U.S. Currency -DRI351B1

Highly effective and inexpensive tool for detecting bad bills. Simply make a small mark on U.S. currency. Chemically sensitive ink works instantly. An amber mark passes the test . while a dark brown or black mark fails . meaning the bill is likely counterfeit. Works on all new design U.S. currency (bills series 1959 and later).