Handy money tester pen to protect against false banknotes. Reliably detects counterfeit money within seconds, which is usually printed on normal, starchy paper Simply mark banknote with the banknote checker in a bright place: a clear to yellowish discolouration means "banknote genuine", a brown to grey colour may mean counterfeit After testing on non-starchy paper, i.e. on real banknotes, the marking becomes largely invisible again Suitable for all currencies (exceptions currently unknown) In order to have absolute safety, a note tester should also be used