Quata 1. Long press the [SET] button for 2 seconds, 24Hr flashes, press the [ALTI/+] button to switch between 24Hr or 12Hr 2. Press the [SET] button to enter the setting, at this the hour digits flash, press [ALTI/+] or [-] to set the hour value 3. Press the [SET] button to flash the minutes, press [ALTI/+] or [-] to set the minutes 4. Press the [SET] button to flash the calendar year number, press the [ALTI/+] or [-] button to set the year value 5. Press [SET] button to flash the calendar month number, press [ALTI/+] or [-] button to set the month value 6. Press the [SET] button to flash the calendar date number, press the [ALTI/+] or [-] button to set the date value 7. Press the [SET] button to flash the temperature unit Celsius, press the [ALTI/+] button to switch between Celsius or Fahrenheit 8. Press the [SET] button and the air pressure unit HPA flashes, press the [ALTI/+] button to switch to the air pressure unit HPA/inHg/mmHg 9. Press the [SET] button to flash the height unit M, press the [ALTI/+] button to switch between the height unit M or FEET 10. After the setting is completed, press [HISTORY] to exit the setting state, or automatically exit the setting without doing any operation within 10 seconds colour:Black grey Material:ABS size:9 x 5 x 2cm Package Contents: 1 x altimeter barometer 1 x Instruction manual 1 x CR2032 button battery (not included) Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.