Classic and no surprises.
2 - Use:
Simple.
3 - Measurement results:
Surprising, enough to say that the doctor who calls you a disturbing pressure is goofy. Consequently, I believe that this device deserves an initial calibration (to do before first use). There is no explicit mention in the instructions and practice. All this is very annoying for really sick and fellows who discover, self-control, healthy (apparently).
4. Conclusion:
I regret my purchase and I do not recommend it unless I am informed clearly a necessary system initialization procedure.
How can such a device be approved WHO?