Large transmission range The hygrometer thermometer is connected to a radio transmitter which offers strong wireless signal penetration (433 MHz frequency). The thermometer has a wide transmission range (30-100m/98-328ft) in the open area, the signal can be received quickly and in time in the transmission area.Multifunction indoor and outdoor thermometer for healthy living, measures indoor and outdoor temperature and humidity values. Mainly used to measure temperature and humidity in homes, offices, workshops, etc. Accurate Reading & Large LCD Display Large LCD screen for easy and clear viewing. Indoor Temperature (0-60C/32-140F) / Outdoor Temperature (-40C-60C/-40F-140F), Humidity (10%-99%) and accuracy can reach 1C/5% Automatically update data every 60 seconds (about 30 minutes to stabilize the sensor).Easy to use : it is easy to change with the button at the top on the temperature units in Celsius or Fahrenheit. Please note that batteries need to be re-installed after changing C/F temperature units.Portable design & easy installation : With wall bracket and retractable bracket on the back, easy to mount on the wall or put on the table. Digital hygrometer thermometer is an ideal life partner for your family.