DEAD ON ARRIVAL. Does not power up. Tried with 3 sets of brand new batteries. Was careful to note their proper orientation. This pulseox is useless, dead, doesn't work. Crap. Buyer beware.

Unable to install battery as spring was on same side for both positive and negative terminals so that negative had nowhere to make contact

Don't waste your money, it does not give accurate reading. I would give ZERO starts if I could. This seller should not be able to sell this faulty product. It never registers above 91-92%. Compared with healthcare grade equipment showing a reading of 99% at the same time for comparison. Don't rely on this pulse ox, it's garbage.

I was willing to overlook the cheap plastic-y feeling, but this pulse ox machine barely works. The only way I got this product to turn on is if I don’t put the cover back in the battery compartment. It won’t register my finger unless I hold it all the way open and rest my finger on the sensor, and half the time it’s a poor reading even while completely still. I will be returning this product, this is not practical for my work as an RN.

Doesn’t work. Neither did the replacement. This thing is garbage. The first one I ordered wouldn’t turn on despite trying multiple types of AAA batteries (thinking maybe the problem was the batteries at first). Sent it back for a replacement and that one doesn’t turn on either. I read the instructions and there’s no trick to it. So now I have to send back a second one. Such an unbelievable waste of my time and money. Wish I could give zero stars.

It came broken and it's very cheap!

Brought to my doctor to compare against a real oximeter and this wasn't even close. Completely erroneous readings. Not safe for someone depending it.

This product was used! It has scratches on display and has no wrist/neck strap as described. Packaging was very obviously opened and repackaged. Will be returning for a NEW replacement!

I just received the oximeter and installed 2 new AAA batteries. It doesn’t work at all whenever I tried to hold the button or replaced the batteries. I am disappointed for the quality of this product. Will return it and buy other brand.

Just arrived. Opened the box, popped in batteries - and the power button does not work. The device briefly turns on when you first insert the batteries, and will take a reading, but after it shuts off, it won't turn on again unless you remove and reinsert one of the batteries. Power button does noting. Back it goes.