Product works as advertised and appears to show even the slightest increase in the levels as I tested by taking a few breaths of 95% compressed O2 and watched my level increase by 3% very shortly thereafter.
The instructions were in cryptically poor English, to the point where it was difficult to even know which side of your finger the device wanted pointing up, and the case was so fragile that putting your finger in too far caused the sides to separate
The case that comes with is great at keeping the tool clean
It arrived with a nice little travel case and a little lanyard hook
It came with 2 AAA batteries, a lanyard and a nice protective case.
Also has a handy carrying case included which makes the devise available at anytime.
Some reviewers say that the oximeter is hard to read when their fingers are turned out and away from them...and honestly folks, I really had to laugh at those reviews
I am happy with the pulse oximeter as well as the convenience of the carrying case.
The oximeter worked initially, but when I tried it again couple days ago, it didn't work.
This pulse oximeter fell apart after a few weeks of regular use.
The Pulse Oximeter is important to personal health in the age of COVID-19
Also, the batteries they included were essentially dead.
I can not vouch for accuracy over time, but I imagine that there is not a lot that could cause that to degrade other than maybe a failing battery or dirty sensor
I placed the batteries in the machine and almost burned and caught on
Out of the box with fresh batteries, the device measured pulse and oxygen about 20% lower than the device used in my doctor's office.
I tried replacing the batteries and still does not work.