Small kids on flights can be a problem for everyone.
No passenger wants to sit next to an annoying child, and no parent wants to suffer their own tantrum-throwing offspring, either.
Over the years parents have tried many solutions to the delicate issue of their children on flights, from handing out lolly bags as a pre-emptive apology, to doping kids up with cough medicine, to designing contraptions designed to keep small children asleep for the whole flight.
Some airlines have banned children altogether from some areas of the cabin.
But none of them are as simple, or more ingenious, than this one.