The Extech 445580 humidity and temperature pen features a compact design ideal for field use. With a range of 0-100% RH and basic accuracy of ±5% for humidity, and temperature range 32-122°F with accuracy of ±1.5°F, it simultaneously displays temperature (°C/°F) and relative humidity with maximum resolution of 0.1% RH and 0.1°F.

Additional features include MAX/MIN, data hold, and built-in self calibration utility that allows field calibrations using optional relative humidity calibration bottles (included in 445582 kit). Perfect for HVAC technicians, facility maintenance, and environmental monitoring professionals requiring a compact, easy-to-use measurement tool.