Integrated Sensors for Temperature and Humidity Measurements in an Indoor Environment. Wireless Transmission of Recorded Readings to Android devices, iPhone, iPad Using Bluetooth Smart LE Communications. -20°C to 70°C and 1% to 90% RH Measurement Ranges with a ±0.21°C and 2% RH Accuracy. (2) User-Replaceable AAA Alkaline Batteries with 1 Year Life (1 Minute Sampling Rate). Stores up to 84,650 Measured Readings with Date/Time Stamp if Bluetooth Communications Not Available. Includes Command Strip, Double-Sided Tape, Hook & Loop Strap and (2) AAA Alkaline Batteries. HOBOmobile App Available on the Apple Store and the Google Play Store.