Upgraded 3 Wireless Sensors Thermo-Hygrometer- Capable of displaying readings of up to 3 outdoor remote sensors to monitor multiple locations, looping through every 5 seconds. Equipped with a 4.0" large screen, displaying indoor/outdoor temperature and humidity, temperature and humidity Max/Min records, arrows indicating temperature and humidity trends and indoor and outdoor low battery indicators 4 HIGH SENSITIVITY TOUCH BUTTONS- Light up the backlight (automatically turn off within 10 seconds to save energy); read temperature and humidity from one of the 3 channels/re-sync or re-pair devices; check past or last 24 hours temperature and humidity/switch or ; view Max/Min record and clear data High Reliability and Accuracy- The digital thermometer hygrometer is equipped with multiple sensitive vents, which respond quickly every 10 seconds, providing daily health care assistance for you and your family. Indoor temperature range: -20~70, outdoor temperature range: -40~70, humidity range: 20%~95%, accuracy: 1/5% Multiple Mounting Options- The indoor hygrometer thermometer has desktop, wall mount and magnet mount designs. Outdoor sensor with hook, wall mount and retractable bracket on the back, IPX4 waterproof rating, can be hung on a tree or easily mounted on the wall. All powered by 2 AAA batteries (not included)