The filler caps for water and fuel on my boat use a winch handle to undo them, but you need several turns to undo them, which is basically not possible with a 1 foot long handle! So I needed something smaller. I found the original filler cap wrench by Beoga, but the handle was still too big, so I remixed it with a smaller key style handle.
Just to add, it floats if you drop it overboard as well, which is better than the winch handle does!
I've made a print vertically and horizontally (so that the grain is across the key or up/down the key) and it does't seem to make a lot of difference to the strength, they are both good enough :)
I tend to print the key upright with support for the lugs only and support only from the bed as this seems the neatest route, but if you slowed the print down it ought to print with no support at all (I am impatient and print it at 100mm/s!)