For lens inspection and progressive lens mark identification. It is small, light-weight and doesn't need to be plugged in. Because it's portable, it can be moved to where it is most comfortable to use.The unit is powered by a single 9-volt battery.The majority of progressive lens manufacturers employ laser-etched molds to help opticians identify the manufacturer, lens style and add power of the lens . The BPI Mini ID Tech uses a multi-LED light source with a multiply crossed Foucault knife edge pattern for improved viewing of those marks.Product code:18302