Our U81D Blood Pressure Monitor adopts the newly upgraded chip of the U-series and uses the oscillation measurement method to make the error accuracy of the measurement data only 3mmHg. The compact appearance is very convenient for the home, and the LED screen size is just right to display the date, IHB, and WHO blood pressure indication. In addition, the one-button measurement function is very convenient for use, and the two- 90 sets memory function records more data to manage your health. There is a user button that can be switched at any time. Power by 4* AAA batteries and charging by fast Type-C port. The unique blue backlight can be customized.