This is a little holder for pins, so you can attach them to necklaces or chains. It should work with most pins, but it may need some modification if the pin you want to use is particularly large or oddly shaped.This was made with the default Windows 10, 3D Builder, and is easy to modify should you need to.

Also know, if you plan on printing this thing, you will need supports to be turned on. Another note, is that if you plan on actually, actively using this to hold a pin, you should make it on the highest quality your printer is able to make use of.