One of the best on Thingiverse. I printed on a Replicator, and the fit is very satisfying. I did spend a bit of time sanding. Even so, I broke the pin on the ring, it is a little weak at the base at 10% infill. Once I realized what little bits to sand down, the second one was much easier to install. I did print the second ring at 50% infill, but it is more important to sand down the locking tabs.
Now I have two, because the first was easy to repair with super glue.
Be prepared for a lot of printing time. The ring itself was about 6 hours on a Replicator at .2mm layer height and 10% infill, with slightly reduced rates. =-O