Down-voted? Almost anywhere else in the first world you travel from the US, the required adapter is about the size and shape of a matchbook, and easily slips in

Down-voted? Almost anywhere else in the first world you travel from the US, the required adapter is about the size and shape of a matchbook, and easily slips into a side pocket of your roll-on bag or laptop case. For these UK monstrosities, there's no such hope, so you have to put them in the main body of your roll-on, and because of their 3-D nature, they interfere with the normal bin-packing of shirts and pants. Try it some time; I'm speaking from experience. And if you want to take two, you're really screwed.