For opening doors without touching and therefore minimizing the danger of infection with Corona / Covid-19 or anything else... There are already different of these "grabbers door opener handler hook latch puller tools" around here!
My thoughts:
Nothing beats the elbow for instant using latches/handles and pushing doors open. Problem is having to pull the door (or other stuff like cabinet doors,drawers, windows etc).
And since this shitty pandemic will probably won´t go away very soon I didn´t want a big tool I always have to think of when I leave the house or I might loose.
My focus was on making one as small as possible for making sure to have it with me anytime on the keyring. Also good: saving material and print time - so you can print a lot and give them to others.

Updated version "Corobiner9-7":
While testing I didn`t like slipping of handles with the hook - so I optimized the shape to easily add common rubber bands - it is much more convenient.

Also I added a case "Corobiner9-7 hull" for hiding the hook after using for better hygiene. (a common rubber band will keep it in the case). Simply use the keyring as axle. If it is too wide- you can just scale it a bit in your slicing software.

In file "Corobiner9-7_4Stck" the pieces are touching each other slightly so they are stabilizing themselves on the buildplate - but can be twisted for seperation after printing.

In general the files are modeled so they can be printed even with a wide nozzle (0.8mm >>faster)

With the front of the hook you can push buttons in public spaces.

Print and share! Feedback welcome!