This Samsung Powerbank MUST even be transported in hand luggage.
It is a lithium battery. These are not allowed in checked baggage. This has been banned by the Federal Office of Civil Aviation. The same rule applies to the vast majority of airlines (of the vast majority of nations). See
https://www.bazl.admin.ch/bazl...

if you mean hand luggage on the plane: please check with the airline!

Works, battery is 15 cm long 7 cm wide. Weight 210 grams

In terms of size and weight, yes, no problem, it can even be carried in a pocket. As for air travel, here are the restrictions: https://www.bazl.admin.ch/bazl...

Yes, I've had it in my hand luggage several times. No problem. Didn't even have to take it out.

Yes, compare here: https://ch.hama.com/tipps-und-...