I do find this product easy to use and unobtrusive. I hardly know I'm wearing it. But we did wonder why my heart rate would spike and eventually learned it was when we were in the car, so the road vibration made it give inaccurate heart rate readings. Especially on bumpy gravel roads (on our way to the forest). So that was good to know. I still think it's very awesome for tracking O2 and HR while sleeping, which is the primary purpose I bought it for. But I think the company should say that the HR readings can be inaccurate with activity levels. My HR would go up to 160 on the bumpy road and then go straight down to 60 when we stopped. After several times like this, we realized that it was picking up vibration from the road. Good thing to know, as it was very worrisome at first. Otherwise I would have given 5 stars. Still a great product.

Overall, using this for several nights has told me what I needed to know about whether my CPAP is doing an adequate job of maintaining oxygenation. The exact accuracy of the reading cannot be confirmed, but at least I believe the size and frequency of the dips in oxygen saturation and the number of times a dip produces an arousal from sleep based on pulse changes or motion. I have the medical and engineering qualifications needed to interpret this. The silicon ring fit comfortably on my little finger (large bones) and the tightness was tolerable for one night on my ring finger. A true sleep study would be much more expensive and some fraction of that would be out of pocket. And there were delays and hassles in getting it scheduled. So I opted for this and am satisfied.

Minor issues include the difficulty for an elderly person to fasten the wrist band - 2 short metal obelisks go through evenly spaced holes on the other band. Also, establishing the blue tooth connection each night is not a smooth process, often taking 2-3 minutes of hassles.

Beware that the promised "free return" only applies to an unopened package.

While staying with parents noticed difficulty sleeping at night. This device confirmed the desatting 70-80s which is dangerous. While my Dad is in rehab, I just asked for supplemental O2 and he is now 98% the entire night.
What's great about this device
1. Comfortable rubber ring. Not bulky. Use it on the 3 finger. The wrist band is big. You could wear a sweat band to take off the slack. We have Wellue To O2 unit and this one. The ring is bulky and very noticable on the finger. This rubber band unit is not comfortable as the main part of the unit is on the wrist.
2. Accuracy matches a finger O2 Heart rate device and match the hospital grade devices. It won't capture skipped beats from AFib but few devices do, unless you have an EKG w leads.
3. The battery life is great and can last multiple nights so we don't worry if the device will run out before the end of night or if we forget to recharge one night it will still work the entire night.
4. Monitoring on the app using bluetooth on another room. This is key if someone else is monitoring the person.
5. Alarm system for O2% or Heart rate. The app will alarm to the parameters you set for O2 and heat rate. You have the flexibility to set the O2 to whatever percentage. Maybe you want 90 vs 88%. Or heart rate at 40 and below. The app will alarm on our Android device (use a cheap Android Lenovo tablet). The device itself will beep and vibrate to wake the person up. So if you are self monitoring, this is great so you wakeup is you are oxygen starved. But you could change your position to improve your oxygenation.
6. This produce a report of O2, heart rate, and movement over the entire time it is worn. It gives you% of time in ranges of O2 and Heart Rate. Number of times you drop in hour. Very helpful information to ensure good sleep. Once you disconnect the device it will give you give down of 10sec to reconnect. When out, the session will end. When you select History Tab on the app, the down load will begin.
Some changes
1. The charger is a proprietary or difficult to find connector. Wish they could upgrade to even a micro USB (older than that)
2. Wish the report had more heart rate about lines (30, 70, 110). You have to extrapolate from 30-70. You can rollover with a mouse on the app and it will tell you the value. But the pdf is a flat report. Wish it had the faint lines of 40, 50, 60 etc.
Overall, great device. Huge help. My father is more alert and knowing he stays oxygenated during his sleep has improved his activity and concentration levels but also improves organ, heart and brain health.

This is a great monitor. Had read other reviews that indicated the meter was not accurate. I found that if you wear it on your thumb as the directions show then the meter is dead accurate with my other finger pulse/ox meters. But this meters true worth is monitoring the night/sleep mode. fabulous. would highly recommend it for any and all patients who wear supplemental oxygen at night.

The customer service is reasonable.
Picks up O2 drops missed by IWATCH 6 and ring device.
The device reads a couple of points lower in some positions compared to the ring device and regular pulse oxygen fingertip one.
To get the alarm to play through the phone it seems the screen setting needs to be set always unlocked? This is loud enough to be a good tool.
The higher pitched the sound from the device is not sufficiently strong to alert,when asleep.