I just received my ring in the mail today and I am so excited to start wearing it, especially with my Caine-centric outfit of choice! The only snag was that I was not aware what a ‘registration key’ was in terms of 3D printing. There was some brief confusion on my end until I realized that I had to remove a protective piece of plastic to expose the groove where the ring itself goes. The reason I am saying this is to kindly suggest to the maker that a visual diagram accompanying the info sheet would be much appreciated. Other than that, this is still a very cool purchase that I will very much put to good use. Thank you for making these!