This is a hanger.

Yep.

Made from 3 parts, hexagonal base and two hooks push-locked in the base. Why 3 parts? To obtain better hook strength. Is it overengineered? Yes

The holes are for M4 wood and wall mounting screws, but I was able to mount them also with M3 screws with reasonably wide heads.

It was created for people

like me who are too impatient to just remove coats from the injection molding hangers like you should, and just pull on the coats instead of removing them from the hooks, to save .5 seconds every time you are doing this. Therefore lower hook has only minimal “locking curve” to just hold the hanged stuff enough, but still allow to just quickly pull the stuff without breaking the hook.

It has hooks

Two exactly, lower flat hook for normal use and upper, longer, more curved hook for other things.

Can I swap the lower and upper hook?

I mean, this is free country, but it was not designed to be operational that way, so probably won't work as the hooks will collide.

Known issues

- Can print only on ≤0.4mm nozzle, .6mm might not produce the locking mechanism wall
- Occasionally the locking mechanism wall might break when assembling. In my experience 95% of prints do not have this problem, but keep this in mind
- Model could use a bit more optimization for hole and locking mechanism tolerances.