Barometer: Displays current barometric pressure immediately after power-on. Press the [ALTI/+] button to switch between barometer and altimeter modes. Altimeter: Shows sea-level altitude of the current location upon startup. In altitude display mode, press and hold [SET] and [ALTITUDE/+] simultaneously, then use [+] or [-] to adjust the displayed altitude value. Relative Altimeter: Resets the current height reading to 0 meters, establishing that position as the reference point. Subsequent elevation changes are displayed as relative altitude. To reset, press and hold [ALTI/+] until “0M” appears at the bottom of the screen, then begin moving—the screen will show relative altitude changes. Press and hold [ALTI/+] again to return to absolute altitude display. Weather Forecast: Provides a general weather trend prediction for the next 12–24 hours based on local atmospheric pressure changes. Effective range is approximately 30–50 km. Time and Settings: 1. Long-press [SET] for 2 seconds to toggle between 12-hour and 24-hour time format. 2. Press [SET] to enter time setting; hour digits flash—adjust with [ALTI/+] or [-]. 3. Press [SET] again; minute digits flash—adjust with [ALTI/+] or [-]. 4. Press [SET] again; year digits flash—adjust with [ALTI/+] or [-]. 5. Press [SET] again; month digits flash—adjust with [ALTI/+] or [-]. 6. Press [SET] again; date digits flash—adjust with [ALTI/+] or [-]. 7. Press [SET] again; temperature unit (°C) flashes—press [ALTI/+] to toggle between °C and °F. 8. Press [SET] again; pressure unit flashes—press [ALTI/+] to cycle between hPa, inHg, and mmHg. 9. Press [SET] again; height unit (M) flashes—press [ALTI/+] to toggle between meters and feet. 10. Press [HISTORY] to exit settings, or wait 10 seconds for automatic exit. Color: Black/Gray Material: ABS Plastic Dimensions: 9 x 5 x 2 cm Package Includes: 1 x Altimeter Barometer 1 x English User Manual 1 x CR2032 Button Battery (battery not included) Note: Actual product color may vary slightly due to lighting and screen differences. Measurement tolerance: ±1–3 cm.