Checkme™ O2 Sleep Monitor - Wearable Oxygen & Heart Rate Tracker - Patented Thumb Sensor - SpO2 Pulse Oximeter with Smart Vibration Alarm - Bluetooth - Anti Snoring - Sleep Apnea Aid Wristband

It’s ok but not too sure about accuracy

I bought this o2 monitor for my ME/CFS. It works really simply, just switch it on at the side and select night or day and before you know it you have your pulse and o2 sats being monitored. The app viheath is simple to use too. You have to enter the serial number of the device first. It says it is written on the back of the device. However I couldn't find it. But thankfully an email to customer service solved the problem... The device actually comes apart. It is providing invaluable information for my doctor. Already I can see I dip to the 80s during the day and overnight. The one slight negative is the thumb ring is a bit flimsy. I don't think it will last long. I see you can buy a replacement separately which is helpful.Edit July 2020: I was wrong about the thumb ring, it's still intact all this time later! The device has been invaluable during my coronavirus illness. My o2 sats are still affected 4 months on. Oh and a friend of mine who has suspected sleep apnea wore it for a week. It clearly shows he has a severe case. I have upgraded my review to 5 star.Nov 2022: This device is STILL working! I have checked it against a hospital pulse oximeter and it is accurate. Also the respiratory consultant accepted the graphs from this device.