And I don't mean that term in a derogatory fashion, I just mean kinky people. As this thread will be directed at them. I don't imagine i'll get a very high amount of traffic here since it's kind of a "niche" topic, but I figure i'd throw it out there anyway. Has anyone heard of or had experience with something referred to as an "eternity collar"? (Picture for reference.) It's basically a metal collar that locks into place by use of a screw that's tightened down by a small allen wrench. My girlfriend is looking into getting one for me. I think it's a pretty nifty concept, since without the O-ring attachment, it could just pass as nothing more than an odd piece of jewelry.