Good measurements, battery consumption so-so. On the dial, if the oximeter is on the side, the black numbers are hardly visible at all. Perfect for the money.

I bought it from a pharmacy and I paid about €20 more expensive. No comment... After a few days, it didn't work everywhere. It worked at my house, but it didn't work in the village. I returned it and it worked. It probably had something to do with the altitude. If I had paid €8 for it, I wouldn't have cared so much.

Very unreliable in its measurements. It loses many units in saturation. In a hospital setting, saturation was 97-98 and in this device it was 94-95. At times, it would have sudden drops and inexplicably show a saturation of 89-90. I did not find any difference in pulse readings. This may be due to the fact that it is very loose on the finger, especially for someone with small fingers, causing the measurements to easily fluctuate. You can find much better options for €5. It is not worth spending money on this thing.