I needed something to put my mailbox key on that could separate from the rest of my keys so I don't have to shut my car off while I check my mail.

Print and enjoy. You shouldn't need any support at all.

I just uploaded keychain_clip New Design v4 which has a larger loop at the top.

Unlike the original this one is bi-directional. I've also updated the design even more to use less plastic and hopefully print without any overhangs. Download the "New design" files and scale to your liking.

I printed with 5% infill and 0 extra shells. Print with more infill if you want it stronger. It seems plenty strong for me at 5% infill.

I'm going to resize mine to .75 so it is smaller on my keychain. I've uploaded regular size and .75 sized too.

I've printed one at .50 scale and it works ok. If you print it that small print it with 0 shells so there aren't any fill problems.

This thing was made with Tinkercad. Edit it online https://tinkercad.com/things/edwKIy1tJ7t