Just did a bit more searching and found this site that seems to have a product, though I'm not sure if it is actively in production and available. Source: over 2 years ago

Jewelry (ring, necklace, bracelet, earring) seems perfect for physical authentication devices: it's easy to carry, always available, and hard to lose. In the middle ages nobles used signet rings to stamp official documents with their unique personal pattern. In modern times, you can stash a Yubikey in a bulky wristband or put it on a necklace chain, but these are not very stylish. There are a variety of "smart... Source: about 3 years ago

My only complaint is sort of a double edged sword. The "Armor of Aquilla" ability, I really really like. But, I can see some potential issues with it. This ability gives you a 50% chance of rolling an effective defense. With Riechsritter Kavallerie, for example, 5 dice at 50% chance to roll an effective defense is quite high. A quick probability tester (omnicalculator.com) shows that there is a 50% chance to... Source: over 2 years ago

Edit. Found one on a site called omnicalculator.com.... Source: over 2 years ago