1736 Wireless Thermometer, Sensor Temperature Range -40 Degrees to 140 Degrees F/-40 Degrees to 60 Degrees C, 20 Percent to 95 Percent, Number of Sensors 1, Transmission Range 200 ft, Primary Scale Outdoor Temperature/Humidity, Includes NIST-Traceable Certificate No, Base Power Source Details (2) AA Batteries, Base Temperature Range -40 Degrees to 140 Degrees F/-40 Degrees to 60 Degrees C, 3 1/8 in H x 4 3/4 in W 3-Digit Backlit LCD Display - 1 in Digit Height