Identify counterfeit currency and (ick) biological stains. The kids are going to love this. Comes with a built-in white LED light and UV LED light (batteries included). Magnifier has a 2" square lens in black frame; unit is 5" tall. So you can use it as a regular magnifier (threading needles, reading menus), a lighted regular magnifier, and, in the UV setting, checking out some stuff you may not really want to know about. What fun!