"Hello Fat Gearboxes - they're big and they're flimsey".
Can't shove a gearbox in a show bag, or down a clown's mouth for that matter (although you'd want to).
I've demonstarted the MultiTool, Vslicer, Swiss Vege Peeler, mops, juicers and all sorts of crap as a kid. By the time the poor suckers got home most of it would have fallen apart, fun times.
There was a pulley that was demonstrated at A & P shows, you'd lift an engine block up and down with it, that'd be good for all your gearboxes!