In Amazon, I found some helpful advice that “the International Civil Aviation Organization's (ICAO) instructions for the safe transportation of dangerous goods by air that power banks allowed for carry-on baggage in the aircraft cabin must not exceed 100 Wh, or equivalent to less than 27,000 mAh.”

Also, some peoples personal testimonies on this as follows:

• I was traveling with this in my hand luggage. It was detained at the Frankfurt airport. Luckily, I was given the option of leaving it in the "lost luggage" office. But I had to pay Euro 6 and had to collect on my return. Definitely not allowed in an airplane, at least not in Frankfurt airport.
• I have a Poweradd Pilot Pro and it's 32,000MaH. It's bigger than this ROMOSS unit. I bring it to Africa all the time and have never had any xray/security person give me a 2nd look. Dallas, NY, Newark, Paris, Heathrow, Addis Ababa, Amsterdam, Brussels, Rwanda, Burundi, Doah (Qtar). Smart money says these airports won't look at the smaller Romoss unit.