Bright LED: With this dual LED light source, you can clearly see objects in the dark or in low light. The magnifying glass provides a detector for detecting counterfeit banknotes, which is used for banknotes, passports, credit cards and traveler's checks, etc. Pocket size:it is very convenient to carry and you can use it anywhere. It requires 3 LR1130 batteries (Batteries are Included). Function:eye loupe is great for rock collectors, coin collectors, jewelers, hobbyists, and also makes a great gift for the kids to explore the fabulous tiny world. Foldable Design:Just Pull Out the Jewelry Magnifier to Use, and Put It Back When Not In Use. This 40X magnifying glass Illuminated Jeweler Loupe is built from durable metal with an optical glass that is 25 mm in length and has a dual bright LED light.