This portable weather station is composed of a barometer, a thermometer and a hygrometerMeasures barometric pressure (hPa), temperature (C) and humidity (% RH)With metric system. Its superiorities include simplicity, reliability and easy readingNo special maintenance work is necessary during its long term useThis Dial type weather station is made of superior materialsSpecification:Product Diameter 132mm (5.2")Product Thickness 38mm (1.5")Relative humidity 20% ~ 45% RH , 9% RHRelative humidity 45% ~ 75% RH , 6% RHRelative humidity 75% ~ 98% RH , 9% RHBarometric pressure 1060hPa ~ 1030hPa , 10hPaBarometric pressure 1030hPa ~ 990hPa , 5hPaBarometric pressure 990hPa ~ 960hPa , 10hPaTemperature -20C ~ 50C , 2CTechnical Index No special maintenance work is necessary during its long term use.