Sharpie Counterfeit Detector Marker, 3-Count Specially formulated money pens to detect bad bills; reacts to the presence of a key ingredient present in papers that are not used by the US Treasury. Effective on all US currency including new design bills. The ink marked on a suspect, counterfeit bill will change in color from golden brown to blue-black. Contains 3 detecting pens. 0.87 inches long by 4.687 inches wide by 7.562 inches high. 0.17 pounds. Imported. Introducing the new Counterfeit Detector by Sharpie which is specially formulated to detect bad bills The technology reacts to the presence of a key ingredient present in papers that are not used by the US Treasury This new marker is effective on all U.S. currency include "new design" bills The ink marked on a suspect, counterfeit bill will change in color from golden brown to blue-black 3 Counterfeit Detectors (an authentic bill will not produce an ink color change)