Thermo-hygrometer pen. Measures temperature and humidity, simultaneously. Dual display. Temperature in degree F or degree C. Pocket clip. Battery included. Minimum/maximum memory. No of inputs: 1 temperature/1 humidity. Temperature range: -4 degree F to 122 degree F. Temperature resolution: 0.1 degree F. Temperature accuracy: +/-1.8 degree F or 1.0 degree C. Humidity range: 10 percent to 90 percent RH. Humidity resolution: 1 percent RH. Humidity accuracy: +/-5 percent for -40 percent to 80 percent RH. Power: button cell (1) LR44. Measures 1-3/4" length by 19/32" width by 6-1/2" height..