PJIVE’s smart ring puts health tracking in a form you might actually wear all the time. It’s a simple titanium band that continuously logs your heart rate and blood oxygen levels, aiming to give you a baseline of your vitals without the bulk of a watch. The focus is on passive, 24/7 data collection through the companion ECTRI app.

In daily use, the ring is comfortable for sleep tracking, which is where it feels most useful. It breaks down your night into deep, light, and REM sleep stages. The 64MB of storage holds about a week of data before syncing. You do need to manage its unique power source—a single AAAA battery lasts roughly a week and replacements are included. The 2-inch screen display spec seems to be an error, as the ring itself has no screen; all data lives in the app.

For a clear picture of trends in your resting heart rate or nightly SpO2, this works. It’s not for real-time workout metrics. Think of it as a minimalist health logbook for your finger, not a sports coach.