Parameter setting: 1. Press and hold the [SET] button for 2 seconds, 24 hours flashes, press the [ALTI/+] button to switch between 24 hours or 12 hours 2. Press the [SET] key to enter the hour setting, at this time the hour number is flashing, press [ALTI/+] or [-] to set the hour value; 3. Press the [SET] key to make the minutes blink, press [ALTI/+] or [-] to set the minutes; 4. Press the [SET] key to make the number of the calendar year flash, and press the [ALTI/+] or [-] key to set the year value; 5. Press the [SET] key to make the number of the calendar month flash, and press the [ALTI/+] or [-] key to set the month value; 6. Press the [SET] key to make the calendar date numbers flash, and press the [ALTI/+] or [-] key to set the date value; 7. Press the [SET] key to flash the temperature unit, press the [ALTI/+] key to switch between or ; 8. Press the [SET] key, the HPA air pressure unit flashes, press the [ALTI/+] key to switch to the HPA/inHg/mmHg air pressure unit;The altitude displayed on the screen after power on is the sea level altitude of the current location. In the state of altitude display, press [SET] and [ALTITUDE/+] keys at the same time, you can press [+] or [-] to change and set the current altitude value.The method to reset the altitude value is to press and hold the [ALTI/+] button until 0M is displayed at the bottom of the screen, and then start to move, the relative altitude value of the movement will be displayed on the screen, and then press and hold the [ALTI/+] button to return to the actual altitude value.In barometer mode, pressHISTORYkey to view historical barometric pressure records. Whenever you enter this mode, the oldest recording will always be shown. Press [ALTI/+] or [-] key to display the history record forward or backward.