The Triplett RHT22 Hygro-Thermometer simultaneously displays Humidity (10 to 99%RH) and Temperature (32 to 122°/0 to 50°C) on a large, easy-to-read LCD. Temperature readings are °F/°C switchable. Icons indicate comfortable, wet or dry humidity conditions. Min/Max function with reset option records the highest and lowest readings to monitor changing conditions over time. The RHT22 can be placed on a flat surface using its built-in stand or wall mounted in labs, green houses, cleanrooms, warehouses, museums, offices, schools, homes, and virtually anywhere indoor humidity and temperature have to be monitored. Comes complete with AAA battery.