[wide transmission range] the hygrometer thermometer is connected with a radio transmitter and can provide strong wireless signal penetration (433MHz frequency). The thermometer has a wide transmission range (30 - 100m / 98 - 328ft) in the open area, and the signal can be received quickly and in time in the transmission area. [multifunction] indoor thermometer and outdoor for healthy living, measures temperature and humidity values indoors and outdoors. It is mainly used for measuring temperature and humidity in homes, offices, workshops, etc. [Accurate reading and large LCD screen]: Large LCD screen for easy and clear display. Internal temperature (0 - 60C / 32 - 140F) / external temperature (-40C - 60C / 40F - 140F), humidity (10% - 99%), accuracy up to 1C / 5%, automatic adjustment of data every 60 seconds (about 30 minutes of sensor stabilization). [Easy to use]: Use the top button to easily change the unit of temperature in degrees Celsius or Fahrenheit. Please note that after the temperature unit is changed to C/F, the battery needs to be reinstalled. [Portable Design and Easy Installation]: Wall-mounted and retractable on the back, easy to be installed on the wall or placed on the table. The hygrometer digital thermometer is the perfect life companion for your family. [size] host: 6*7.5*2cm, submachine: 5.5*2.5*7.5cm [package contains] host*1, submachine*1, instructions*1