The Extech 445814 Hygro-Thermometer with humidity alarm has a programmable acoustic and visual alarm for relative humidity, which is triggered when the set limit value is exceeded. The large LCD displays temperature, humidity and dew point simultaneously. Measures the humidity from 10 to 99 % rel. humidity, ± 4 % rel. humidity and the temperature from -10 °C to +60 °C, ± 1 °C (14 °F to 140 °F, ± 1.8 °F). Rear calibration potentiometer for humidity and temperature. Equipped with maximum/minimum value and reset functions that store and recall the highest and lowest recorded readings. The scope of delivery includes an integrated stand, a wall bracket and two AAA batteries.