TFA Malibu wireless pool thermometer is indication of indoor temperature and humidity. For pool and pond, transmission of water temperature via pool transmitter and outdoor temperature via outdoor transmitter (maximum 100 meter). Maximum and minimum function. Other features dew point, probe with 100 mm measuring depth, radio controlled clock. Temperature range: indoor -10 to +60 degree C (+14 to +140 degree F), outdoor -40 to +60 degree C (-40 to +140 degree F), Humidity indoor 20 to 95 percent, Pool: -10 to +60 degree C (+14 to +140 degree F). Measures 95 mm width by 158 mm height by 21 mm depth.