There are two types of rings in here. One is wider “mens” and the other is narrower “womens”. Both are set to a 20mm inside diameter. Feel free to go into the Fusion360 file and change the diameter to fit your finger.
These rings are very soft and squeeshy, probably more so than a true silicone ring. It doesn't bother your other fingers.
For printing I'm using SainSmart TPU (in your favorite color), with 2 walls and no infill. I haven't tried it with infill, but obviously the more infill you mix in the harder the ring will be.
The author marked this model as their own original creation.