This is an excellent device to have at home.It's function perfectly and the display has big numbers easy to read. Also it's come with 2 batteries.This is a handy tool to have on hand for when oxygen just needs to be monitored. It's light enough for comfort and in a price range where you don't have to feel you're investing. I don't know if it's the most accurate for particulars, but it's great for home use.Works as expected. I only tested on myself and my mother. I used a blood pressure cuff after and they had very close values so I think this accurate. Then I took the batteries out to store in the closet for later use.Not sure accurate this is but it looks to be reading normal so that's good! It comes with a lil hand lanyard and batteries which is a plus! Everyone needs one of these in their first aid kit!Not quite as accurate as a doctor's but still give you within a few points which works for just checking yourself at home.Simple to use, although having a screen that auto rotated would be nice so you could easily read it whichever hand it is on. But I'm guessing that would push the price past what people would be willing to pay.Screen is clear and easy to read though, and it turns off after a period to keep the battery from running down.After a recent trip to the doctor I have been more aware of my need for monitoring my health. I selected this oxygen meter/heart rate monitor as part of that effort, and so far it seems to work reasonably well.This is a simple device - pop in the batteries, slip it on your finger tip, and turn it on. It's no more complicated than that. It works fairly quickly, providing a readout in 1-2 seconds most of the time. It shuts off automatically when removed.There is a right way and a wrong way to put it on your finger, though. The first time I used it, it gave me a frighteningly low oxygen readout, and it took a moment to realize I had the sensor on a fingernail rather than against my skin. Once I positioned it properly it gave me a much more sane readout.I am not sure about the oxygen level accuracy (I have no way to compare it to anything) but the pulse/heart rate is accurate. I have always had a fast heart rate, and this monitor correctly measures it. The oxygen readout seems reasonable so I assume it's in the ballpark.For the cost this seems like a reasonable solution if you want to measure your blood oxygen concentration and your heart rate. It works quickly and it's an easy device to understand.This is great very accurate read I used it while at the hospital and the numbers were the same as the numbers on the monitor so very pleased with that accuracy very easy to use to popped in the batteries pressed the button on the front and it starts detecting immediately gives you a number in a stable number in about 10 seconds