This practical humidity and temperature meter is suitable for on-the-go use with its durable 3V lithium battery that offers a long usage time. The slim Extech 445580 humidity/temperature pen measures humidity levels between 10 and 90% rH and records temperatures from -10 °C to 50 °C (14 °F to 122 °F). This tool is ideal for field measurements and stores the recorded maximum and minimum values until the memory is cleared. It also features a button for holding rapidly fluctuating measurement data.