Counterfeit detector pen works on all Sterling notes and 200 other currencies worldwide. Grey or Brown mark means the note is suspect and clear or light amber means the note is genuine.
Fake Bank Note Detector Pen PABNB
With this pen, you can easily detect whether a banknote is real or not, ensuring that business is safe from being scammed. To use this pen, simply write on the surface of the note. If the ink remains clear or turns to a pale amber hue, then the note is real; if the ink turns brown or grey you can tell that the note is counterfeit.