H4-V12 Smartwatch for Men& Women Color Screen IP67 Waterproof Heart Rate SpO2 Monitor Health Smart Watches / Sports Fitness Activity Tracker Running Watch Compare with Android & iOS phones (Black)

I've tested this while sleeping and during the day. I wanted a good SPO2 monitor, and heartrate monitor during exercise. If I push my heartrate up to 160-170 range the watch never figures it out. I tested this at the same time with another HR monitor. I do some Wim Hof style breath holding, and the algorithm never recovers if you hold long enough to lower saturation below %90. Lastly, when I get up in the middle of the night, I get false positive apneas from the app. It would be nice if the watch knew to mark part of the SPO2 data as ambulating. That would help eliminate false positives. I recorded times I got up and was awake so I could tell that there were false positives. I do like the product overall. I hope you find the information helpful.

Watch was not as expected, pulse ox did not work most of time and when it did it was not accurate at all. contacted seller and they just told me what pulse ox was. screes will scratch with just your finger, found that out on the first day.Returning product and I have to pay shipping to even return it! Will NOT^ buy from this comapny again!

I like that it's easy to set up and easy to connect

What can I say but I am truly happy on my purchase of H4-V12 as it is serving all my needs. And to have ongoing health updates is so comforting.

Excellent product

Not impressed, notifications doesn't work. You get what you pay for. Lacks good Bluetooth connectivity. Can't recommend this watch.