Question about RAVPower Rp-Pb059

So - a little experiment. Depending on the device and the port to which it is connected for charging, different volts/amps are automatically required or provided by the powerbank. This also applies to recharging the power bank. That is why these different specifications are also in the description. To convert mAh into Wh, you need the voltage of the battery - which is unfortunately not known. If you take the standard 5V and the 20100mAh, you would get 100.5 Wh (formula is: (mAh)*(V)/1000 = (Wh)).
One indication from the manufacturer is that e.g. an iPhone 7 can be charged up to 7x, a Galaxy S6 up to 5x....
Hope this helps a little

The specifications of the product are very clear and answer this question regarding the voltage. Of course this powerbank is suitable (at least for me), but everyone has to answer that for themselves. If the question relates to whether it is allowed to be taken into the cabin, I would advise clarification with the airline. For Europe and all other countries than the USA, I see no reasons against it. I'm flying to Spain in a few days and will certainly carry the battery pack as hand luggage.