The Chemical Detector pen can tell the difference between genuine and counterfeit banknotes in half a second! Make a small mark anywhere on the note – if the mark is LIGHT AMBER the note is genuine, DARK BROWN or BLACK the note is suspect. The light amber marks will disappear in 24 hours so that the note is not defaced. This is how easy it is to use the money checker pen. The Chemical Detector pen is easily carried in the pocket or handbag. It can be used anywhere – even when travelling abroad. In addition to ZAR currency, it will test 200 other currencies world-wide.