Currency detector: Emit invisible 980nm wavelength Green lighting color 100mW,Portable, Multi currency 2 x AAA battery As one of the most advanced Anti-Counterfeit test tools available in the world now, Infrared Laser Test Pen is a effective currency detector used for testing currency, securities, brand, certificates etc. on the specific area of their surface. 1/It can detect US$ (at $20, $50,$ ...