They are all the same. does not matter what finger. When you se the bar/line going up n down the is your pulse/heart rate. The number with %spo2 that is the % of the air you are retaining in your blood stream. Wash your hands. Make sure the finger you use is warm, if it cold, it will not be accurate. Hang the finger down, some people you have to do this. Do not have in the direct light/sunlight.

I have done the test before, I know I have sleep apna and I refuse the mask. I want to try inspire.com

I have used about 5 different oximeters. They didn't vary much so all gave a close o2 level. What they did differ in was speed. The best one I came across is the Henry Schein brand.

Just a little side note; you don't have to put it on the fingernail side. It actually works better on the padded finger side. Try it!
When I was first diagnosed my o2 would go down to 73-74 upon exertion and I didnt know it yet. I was never out of breath. I would get tunnel vision and weak in the legs, things would get a little gray. I would stop and wait for it to clear up, it was then I heard the little voice in my head to get an oximeter.

Thanks everyone. They had me wear it overnight to see if I need oxygen at night. Before the pulmonologist runs other tests to see if it is something else like sleep apena. So I just wait and see.