Counterfeit Money Detection System, US dollar

Powerful yet compact ultraviolet penlight reveals UV-sensitive security markings on 1996 series or newer U.S. currency denominations greater than $1. Counterfeit detector pen uses a chemically sensitive ink to detect bad bills by marking a line on the bill; if the mark turns dark, the bill is suspect. UV light also works on many foreign currencies, major credit cards, passports, traveler's checks and more.