This small handle gives each Allen or Inbus key a better grip. And the different color makes it easier to distinguish the different sizes.
I have added the standard inch and metric hex key files.
If you need other sized handles use the customizer here and set the "Bottom Thickness" to 0.
Here the settings I used:
Support: touching build plate (the easy print hex style needs no support)
UPDATE: all files regenerated. There was an error in calulation of bigger nuts in the generator.