Barometer and Altimeter:With Barometer Altimeter,the air pressure value on the screen is the air pressure at current location,height value is the sea level of current location.Press ALTI/+ button can switchMaterial:Digital Altimeter Barometer made of ABS material,is durable and long-lasting,wear-resistant for long term useWeather forecast:Digital Altimeter also helps to forecast the weather for the forthcoming 12 to 24 hours basing on barometric pressure changes with range 30-50kms apart from detecting the altitudeSave power design:Digital Handheld Barometer can stop all display enter into dormancy mode by pressing and hold SET button for 5 seconds, it can give backlight for 5 seconds that you press any buttonHistory altitude record:Barometer Altimeter Thermometer can save most 256pcs records,and you can change the distance from 1-60 minutes if you press and hold HISTORY button for 2 seconds