Dri Mark Dual Test 351UVCL - The Original Counterfeit Detection Marker Pen with UV LED Cap, Tests for Security Strips and Authentic Currency Paper - 1 UV Light/Pen Combo Plus 1 Holder with Coil

The Dri Mark Counterfeit Detector Pen is your best first defense against loss due to counterfeit.An essential for any retail business accepting cash.Simply uncap the pen and make a small mark on US currency.If the mark turns dark brown or black, the currency is suspect.If the mark remains light yellow, the bill passes the test.'