Small LED lights show the status of the battery.
The second function is very original: a UV light source that can be used both for testing the authenticity of bank notes (see photo below) for detecting various soils. If the traces of my cat, animal a maniacal cleanliness, proved to be very visible, for finger marks against children (less obsessive cleanliness ...) appeared to me at the outset to sometimes unexpected places . The "crimes" were immediately signed!
As usual with RavPower, the finish is very nice, smooth and pleasant to the touch.