Made for a friend of mine. A little known fact: I myself am an avid rock climbing and have been at it for over 10 years as of this writing. I currently spend a lot of time bouldering at a local bouldering gym that I helped to design and build.
The ring is modeled after a common climbing knot: the Figure 8. this is the most common knot used as the direct safety tie in point to your harness. A symbolic ring which to me represents the tie between two people... a safety line so to speak.