This highly effective tester pen is used for detecting fake bills and deterring counterfeiters from passing fake currency. Just simply make a small mark on currency and the chemically sensitive ink works instantly. The amber colored mark passes the test, while a dark brown or black mark color means the bill is counterfeit. Small and compact for portability. Perfect for all businesses Feature - Color: Black. - Material: PP. - Size: Approx. 13.2x1.5x1cm. - With light UV ink, you can write on the banknote with hidden marks. - When you mark the banknote, it will turn into other color. The ligth yellow or clear color means the banknote is real and the brown or black color means the banknote is fake. - Lightweight and portable size, easy to carry. - Just simply make a small mark on currency and the chemically sensitive ink works instantly. - The counterfeit detector pen is the simplest solution to instantly identify counterfeit bills, convenient to use and check the results in seconds. - Practical tool in daily life, help you to detector true and counterfeit money, can be applied to many occasions, such as stores, small businesses, farmers markets and retail stores, etc. - Warm Tip: Dear buyer, due to lighting effect, monitor's brightness, manual measurement, etc., there could be some slight differences in the color and size between the photo and the actual item. Sincerely hope that you can understand Thank you