The Extech 44550 is a pen-style humidity and temperature meter. It has a dual LCD that displays relative humidity and temperature simultaneously (°C/°F switchable). This temperature pen monitors humidity from 20% to 90% ± 5% and temperature from -10°C to 50°C ± 1°C (14°F to 122°F ± 2°F). It is small enough to fit in your pocket and allows you to take accurate measurements anywhere. The maximum/minimum memory functions display the highest and lowest readings for both metrics. Comes with a pocket clip and one LR44 button battery.