MMF Industries 200045304 Counterfeit Currency Detector Pen, 3/Pack MMF200045304 MMF 200045304, The quick and simple way to prevent fraud by detecting counterfeit currency. Ink works to react with the starch in wood-based counterfeit paper to leave a darkmark and expose false currency. Just mark a small line on bill and observe results: Amber indicates a genuine bill, while black/dark brown means bill is suspect. Features naturally-occurring, long-lasting antimicrobial technology, which protects against te growth of bacteria on the surface of the pen. For best results, replace cap immediately after use. Counterfeit Bill Detector Type: Pen; Marking Color: Amber; Counterfeit Indication Mark: Black/Brown; Currency: U.S., UPC 078541167070