Product ParametersElectronic Altimeter (Weather Forecast + Altimeter + Compass + Barometer + Clock + Level + Calendar) Blue Backlight 8 in 1 Function. Size: Approx. 9 x 5 x 2 cm Measurement RangeThe measurement range is from -700m to 9000m (the altimeter can be initially calibrated), with a resolution of 1 meter. Barometer: The measurement range is from 300 mbar to 1100 mbar, with a resolution of 0.1 mbar. Electronic Compass: 8-Azimuth Mode Display. Thermometer: Measuring range -10C. ~ + 60 ( and units optional) Outdoor EquipmentThis electronic thermometer is an ideal and simple choice for outdoor sports enthusiasts, and the detachable power cord makes the digital compass a perfect handheld device for various outdoor activities. It will provide you with a backlight when you press any button at any time Power SupplyThe handheld altimeter is powered by 2 AAA batteries (not included), which can be used continuously for a long time and is very convenient. Wide ApplicationThe electronic GPS navigation altitude is suitable for outdoor places such as mountaineering, camping and mountaineering. Note: The altimeter should not be used in wet environments