What a coincidence! Had an appointment today with the family doctor, was already in the shoes to drive off, as heralds of the DHL messenger and brought the device. I took advantage of, took it fix in operation and with the Doc. Compared values between manual measuring the Doc and the device. Doc has 122 measured at 81 when pulse 78, unit was 120 at 81 at 79 pulse. So you can truly live. So fully recommendable device. In addition: Delivery in only 1 day from ordering. "Better never goes"! Therefore, the full 5 - ***** !!!