Long Distance TransmissionThe hygrometer wireless thermometer comes with 3 external sensors (433 MHz frequency), you can place three sensors (IP54 waterproof) in different locations. Their data will be displayed on the same screen without changing channels frequently. Distance between host and sensor: The transmission distance is up to 300 feet / 91 meters (without obstacles and walls), and the effective transmission distance can reach 100 feet / 30 meters (with obstacles). White Backlight and Smiley DisplayThe LCD screen displays clear arrows, and you can check the changes in temperature and humidity at any time. The backlight automatically turns off after 8 seconds without any adjustment. The smiley symbol indicates - damp / comfortable / dry. Indoor temperature (0-50C / 32-122F) / outdoor temperature (-50C-70C / -58F-158F), humidity (20%-99%). The temperature and humidity accuracy is 1C / 5%. Temperature and humidity alarm function and calibrationWhen the humidity and temperature reach the preset maximum or minimum value, a sound will sound and the backlight color will alarm (the backlight will turn red and orange). If the temperature and humidity exceed the normal error range, you can press the TIME-SET key to manually correct the error. 5 buttonsOur hygrometer thermometer can record temperature and humidity over a period of time. The Min/Max button can display all the maximum/minimum value data of temperature and humidity. Long press to delete the previous data and re-record. The C/F button can switch between Celsius and Fahrenheit. In addition, there are alarm settings for time (12/24 hour format), date, and upper and lower limits of temperature and humidity. USB power supplyThe remote thermometer has two power supply methods, battery (not included) and USB cable power supply, which is convenient to use and no need to worry about replacing batteries. Battery (USB cable included). The thermometer can be connected through the hanging hole/base. It is very convenient to use. There are hanging holes on the back of the three sensors, which can be easily hung on the shelf. Product size: 18*18*7cm. Quantity shipped: ? 1 piece. Sold in this store