Take this this handy humidity and temperature gauge on the go and rely on a long-lasting 3V lithium battery for maximum usage time. The slim Extech 445580 humidity/temperature pen will capture humidity readings from 10 to 90% RH and register temperatures from -10°C to 50°C (14°F to 122°F). This utility tool is ideal for field work, storing maximum and minimum readings until the memory is cleared and includes a data-hold button for rapidly fluctuating measurements. The meter comes complete with a pocket clip and 3V lithium battery.