Specification:Battery: 2 x AAA Battery (not included)Altimeter:Measurement range: -700 m ~ 9000 m (-2300~2950ft) (altimeter can be corrected for initial test)Resolution: 1 meters or 3 feetBarometer:Measurement range: 300mbar to 1100mbarResolution: 0.1mbar.Electronic Compass:8- azimuth mode displayExternal magnetic field correctionAccuracy: ±3 DegreeResolution: 1 degreesThermometer:Measurement range: -10℃~ 60℃(℃ and ℉ optional)Resolution: 0.1 degreesWeather forecast and time:Weather forecast after 12 to 24 hours .4 weather conditions indicate: clear - half clear - cloudy day - rainy day24 hour format .Electronic backlight: 5 second high brightness blue LED electronic backlight .Warm Tips:1. Avoid using in the rain and damp, high or low temperature condition (temperature: 0℃-50℃; storage temperature:-20℃-70℃).2. Avoid contact with corrosive substances, such as perfume, alcohol, cleaning agent, and so on.3. Avoid being used in a region that may affect the normal direction of the magnetic compass:a: Near concrete / steel and other buildings