I bought this in May, because I wanted to have it in case of covid exposure. I never opened it up. Just opened it today, and it does not work, readings are very low for everyone in the household. Way past the return date, so I can't exchange it. Lesson learned, open your items when received.

Stopped working after 2 weeks.

8 days past the return window of 30 days and it is malfunctioning. It was not used hardly at all and especially compared to the other 2 that are still working after much longer and having been used a lot.

I already own one Contec pulse oximeter. I ordered this one because a friend is sick. This is a fake knock-off and DOES NOT WORK. I am so glad I did not give it to my friend before testing it, because the readings are all very low (85-91), while my real Contec gives me and my (healthy) family members healthy readings (97-99). My friend would have been whisking himself off to the hospital. This one looks a lot like the Contec, but the plastic is different and there are stickers on it instead of printed branding information. FAKE. I will be demanding a refund.

Reads inaccurately many times per day. If readings do not appear correct, you must remove and retry to get a accurate reading. First reading can be off by more than 40 points for both oxy and heart. After retry, it appears to be correct. But which reading was correct?? Since we are not dead it has to be 2nd reading. Accuracy is the difference between safe and calling a doctor and it should not be that way! It sells to be accurate every time!

I have 2 old but trusty fingertip readers similar to this. I purchased this one hoping to have a fancy new graphic pulse display... Unfortunately it reads my blood oxygen saturation level at 70-80-98 while my old ones constantly reads 98-99. Hmmm... 72-80? In that case, I am almost a dead man... Changing to check from different fingers, it reads drastic differences.... Pulse rate reading looks fine, though. Do not make yourself a surprising dead man according to this one's reading... If possible, I will give 0 star....

This machine would commonly creep 6 points lower for O-2 reading, while two other meters held true. I had a 94% on two machines, yet this device 's measurement fell to 89, 88. It would stay there until I removed and restarted the device. Then it would do OK for a while. It was mostly likely to read badly while it was on my right index finger. It was least likely on my right middle finger. Throwing into trash, as the return window is closed.

Seems okay at first but slowly quit working. Slowly started getting hard to power on and stay in. We’ve changed batteries many times and still will not power on. Just bought it 2 months ago.

Great price, nice looking device, so I was excited to get this and have not spent too much money on it as it isn't an essential piece, but something to help monitor my health at home. Was disappointed that this arrived 100% dead. I put brand new, freshly purchased Duracell batteries in them and this thing would not turn on. So I had to order another brand and go through the hassle of returning this one, which is always a pain.

I purchased this while visiting the US to have on hand for meaauring my O2 levels. When I returned home I compared the readings to another oximeter that we have which always provides stable readings. This one varies considerably starting at 97, dropping to 91, going back up a bit. It is too late to return but I will try to dispute with my credit card. In these trying times one needs accurate readings.