Onset HOBO UX100-023 Temperature and Humidity w/ External Sensor Kit External Sensors for Measuring and Recording Temperature and Humidity -20C to 70C and 15% to 95% Measurement Range with 0.21C and 2.5% RH Accuracy LCD Display Shows Temp/RH Measured Readings, Alarm Status, Battery Level and Operating Status User-Replaceable Coin Cell Lithium Battery with a 1 Year Life @ 1 Minute Sampling Rate Kit Includes UX100-023 Data Logger, USB Cable, Battery. HOBOware Software Available as Free Download