Features: 1. The unique ink in the Detector Pen identifies notes quickly & easily. 2. currency: light yellow or clear color mark 3. Suspect currency:Brown or Dark mark appears 4. for testify Bank Notes. These Pens is applied to a suspect Note, which use good ink. when applied to note the ink the color will be dim yellow or clear, however a Fake Note will turn Black/Brown. Specification: Weight: approx. 50g Size: approx. 133*15*12mm/5.23*0.59*0.47'' Color: Black,BLUE(Random Color) Quantity: 1Pc Note: Please allow 1-3mm differs due to manual measurement. Due to the different display and different light, the picture may not reflect the actual color of the item. Thanks for your understanding. High quality assurance: Each product undergoes strict quality testing to ensure that you can provide the best quality experience. User-friendly design: The product features and appearance are carefully designed, easy to operate, and suitable for various usage scenarios. Multifunctional practicality: It has a variety of practical functions to meet your diverse needs and improve the quality of life. Environmentally friendly materials: Made of environmentally friendly and safe materials, harmless to the human body, while paying attention to environmental protection. Excellent cost performance: Provide excellent quality at a reasonable price to ensure a shopping experience that is worth the money.