Check the listing for details. Elitech BT3 Indoor Thermometer Hygrometer Humidity Temperature Meter LCD Digital. Condition: New. Listed at 19.99 USD. Elitech BT-3 Indoor Outdoor Thermometer Hygrometer Temperature Humidity Meter is characterized by the large LCD screen which is designed for easy readouts of the humidity and temperature measurements. 4 Benefits of Monitoring Temp & Humidity Indoor or Outdoor: To keep a certain product fresh in a room like where fruits and vegetables are stored, or a sealed box like a cigar in a humidor; To monitor the environment for fermentation like in beer or winemaking or for incubation of eggs; To ensure the maintenance of good quality in some special personal collections like paintings, guitar or clothing; To give a healthy environment, for example, maintaining a good air quality to avoid dryness on skin and eyes that causes discomfort and breathing-related illness like asthma. Features: 1) Measure and display the indoor/outdoor temperature and indoor humidity 2) Automatically memorize the max./min. values of the indoor/outdoor temperature and indoor humidity 3) Switch between °C and °F 4) Clock function and alarming function 5) 12/24 hour mode switch 6) Recovery function on the max./min. values Specifications: 1) temperature measuring range: -50~ +70°C (-58 ~ +158°F) 2) humidity measuring range: 20% - 99% (relative humidity) 3) Resolution: 0.1 °C /0.1 F ;1%RH 4)Power supply:1.5V DC 7#battery5)External sensor wire length: 2mPackage： 1* Elitech BT-31* External Sensor1* Manual