Sold as 6/Pack. Instantly And Easily Detect Fake Bills - Prevent profit loss with this fast, accurate, effective counterfeit checker. Dual Detector system finds bad bills with the original counterfeit bill detector pen and UV light; An instant and reliable tester for counterfeit currency; Includes 6 Dual Detector Combos UV light pens. Manufacturer 100% Money Back Guarantee: Dri Mark's 90 day Limited Warranty from the date of purchase. You can trust Dri Mark's Dual Test counterfeit money checker for fast and accurate results. U S Patents 8,406,499 and 8,545,766. 2 Tests In 1- Protect Your Profits: Security strip test: powerful UV light is embedded in the cap and is easy to activate; The LED bulb reveals the hidden security stripe found in all 5 dollar bills and higher. Currency paper test: counterfeit marker pen detects genuine US currency paper. Catch a counterfeit bill and it pays for itself. Fraud Detection - Authenticator: Strong, Compact, Simple; UV Light is great for authentica