That’s roughly $1,900 to $2,200. I rack my brain. The most expensive smart ring I can remember is Oura’s collaboration with ...

The wearable-tech company Ultrahuman has debuted the Rare smart ring, which is hand-crafted with 18-karat gold and platinum.

That, however, could be changing with the new Ultrahuman Rare line, which coats its current generation of Ring Air models in metals like platinum or 18-karat gold. Are there other differences ...