Provided with a small cable for charging.
The USB port is good, it keeps taking without forcing.
Four diodes are used to estimate the charge and the time to recharge. This measure in approximate figures of 25% is much more practical than a simple diode loaded / unloaded.
The drum part provides 5 V / 1 A which is enough to charge even a power hungry device like a tablet, but it will be longer than with an output 2 A. Personally I prefer the model 7800 mAh / 5V / 2 A has a superior ability to travel, however this mini-loader has the advantage of being three times smaller and can be worn in a pocket. This equipment is placed after all the troubleshooting niche, while the 7800 model is for a backpacker use more sustained, and compactness is an advantage.
It offers bonus UV light to detect counterfeit money ... or identify traces visible in UV light: urine, blood, mold, etc. Interest is to define everyday if we do not work in forensics. Possibly to clean dirt traces invisible to the naked eye? It can actually be helpful if you have pets. Or why not judge the cleanliness of a used object.
A traditional lamp would have been a more common use ... but on the other hand, to use the lamp too we would end up with an empty battery when charging electronic equipment. And anyway, to help out, the UV lamp also lights, even if it is less enjoyable than a neutral lamp.
Note a very good grip in use lamp in hand.
The value to fifteen euros is very good: it has an effective extra USB battery, and the UV lamp bonus.