This is a heart ring with a concave style band. 

I've include several ring size files. Remember to double check the measurements before and after prints and to scale up or down to desired measurements (adjust using x, y, z scale factors). I recommend printing slightly larger than your known ring size.

Be careful of overly-snug rings!

A correctly sized ring should be able to slide past your finger joint easily without any resistance or force. It may also help to sand down the inner part of the ring to smooth out any existing artifacts that can get in the way. If your finger does get stuck like mine have, one way to remove it is the string/floss method.

There will probably be some stringing after the print- I recommend using a box cutter to go around the inner part of the ring to remove them cleanly!

You can also print other flat shapes or letters to super glue onto the heart surface for extra customization. I've included a file for a dinosaur with hearts that I modeled for this particular project.