Two versions of indicator rings for miniatures on 30mm bases. I am using them for Kingdom Death: Monster miniatures.
I couldn't easily find anything on Thingiverse and this is loosely based on indicator rings that I have seen elsewhere (CMON games, Etsy). I do not have rings from either of these sources to compare against (but the Etsy ones look pretty sweet, character designation rings).
I have included a tight and a loose version.
The tight version will stay on the mini when you lift it up, but will scratch the paint along the edge of the base. I found it difficult to take off, and don't recommend it. Someone might find it handy though.
The loose version is what I am use. It doesn't stay on when you lift the mini up, easy to swap between uses and shouldn't be tight enough to scratch the paint on the edge of the base.