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 Indoor Humidity/Temperature 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 2 in H x 3 1/4 in W 3-Digit Backlit LCD Display - 1 in Digit Height