TFA chilly wireless thermo hygrometer with frost warning. Transmission of outdoor temperature and humidity via transmitter (maximum 100 meter). Bold display of temperature and humidity can be changed to either indoor or outdoor. Wall mounting or table standing. Temperature range: indoor -10 to +50 degree C (+14 F to +122 degree F), Temperature range outdoor -20 to +70 degree C (-4 to +158 degree F), Humidity range: 20 to 90 percent. 1,5 V AAA batteries required but not included. Available in grey and brown colour. Measures 97 mm width by 111 mm height by 19 mm depth.