Ultrahuman Rare is meant to be a luxury, artisan-crafted smart ring. The platinum version costs $2,200.

Ring Air and Ring Rare users will have Ultrahuman's 6-axis motion sensors, temperature sensors, and PPG sensors around their fingers to track sleep, activity, and recovery around the clock.

The words “Rare by Ultrahuman” emerge on a stark ... I don’t know what time is anymore, but I look at the Oura Ring 4 in brushed silver on my finger. Then I look at the desert snow ring ...