Protect your business from loss due to counterfeit money with the Dri Mark Dual Detector. Combines a high wavelength, high intensity UV light, with the dependable counterfeit detector pen. Easy to use, and highly effective, especially against "bleached" bills. All US paper money $5 through $100 have a security stripe which is revealed under our specially designed UV LED. Detect one bad $20, and the product has paid for itself. A necessity for all cash businesses. This special pack contains the Dual Detector, plus 2 replacement pens.