Protect your business against counterfeiters!! The Ultraviolet Dual Test Counterfeit Detector combines the reliability of the Drimark Counterfeit Detector Pen (over 100 Million sold) with the latest in Ultraviolet LED technology buit right into the cap. First make a small mark on the bill. Light amber colored mark means it is authentic US currency paper. A dark or black mark means the bill is suspect. Then shine the powerful UV light through the back of the bill to reveal the UV sensitive security strip embedded in all bills $5 denomination and larger. The security strip in all bills printed in 1996 or later will be a particular color in a specific place on each denomination. Protects against CURRENCY BLEACHING or WASHING which is the most common counterfeiting method used today. Also can be used to reaveal UV markings on drivers licenses, credit cards, passports, government documents, most international currencies, and more. An indispendsible tool for any business with a cash register. Full instructions and currency specifications included. For additional tools and information go to www.drimark.com or call 800-645-9118.