When flying we always have too many objects to deal with between water bottles, jackets, entertainment, and especially kid supplies. I try to avoid using the seat back pocket as much as possible because who knows what was in there previously. This hook is designed to fit onto any size tray table so you can hang some essentials instead.

The biggest challenge when thinking about a design is that tray tables vary in thickness, so a regular hook design won't work.  This design looks like a fairly ordinary hook but it takes advantage of material flexibility using a cantilever spring, which allows it to fit onto surprisingly thick objects while being held firmly in place on any size object.  This also helps keep the overall size down so it easily fits in a pocket or small bag.

I haven't had the opportunity to use it on a flight yet so the photos don't show it on an actual tray table, but I'm looking forward it!