Meanwhile, more wearables measure the oxygen saturation in the blood than leave the display permanently on. The Oppo subsidiary's realme Watch S Pro is also the only smartwatch with an always-on display so far. Our review explains what else it can do and what it has over its predecessor.
https://www.notebookcheck.net/realme-smartwatch-Watch-S-Pro-in-review-Great-display-convincing-runtime.555236.0.html