I wanted to use a key holder but the hole on my key is so wide that the key moves around in the holder.
The tighter fit will be threaded by the M3 screw. The looser fit is still tight enough to hinder any wobble.
The keyholder I use: https://www.printables.com/model/66179-swiss-key-holder
It should fit with any keyholder that uses M3 screws.
The author marked this model as their own original creation.