Usage Tips:About this item Accurate TempandHumid Readings Wireless thermometer for home indoor and outdoor with large LCD display measures the real-time temperature and humidity with past 24 hours Max/Min records and trends arrows. Assess historical data and refer to the Comfort Indicator to quickly know your home living conditions. Works with the hi/lo temperature and humidity alert function, helps create more healthier lifestyle. Come with 3 Wireless Sensors Indoor outdoor temperature and humidity monitor supports to be connected to display readings from 4 different places simultaneously up to 200FT/60M apart (Wireless Frequency: 433 MHz). Monitor your whole home, basement or greenhouse confidently with the digital thermometer and humidity gauge. Wide Measuring RangeInside outside thermometer wireless measures indoor temperature from 50F - 140F(-10C - 60C) , and outdoor temperature from -58F - 158F(-50C - 70C) with 1C accuracy. The indoor and outdoor humidity range is 20 percent -95 percent with 5 percent accuracy. (Wet: humidity70 percent COM: 40 percent humidity70 percent and 20CTemperature28C) DRY: humidity40 percent . ) Max/Min Record and Alarm Wireless thermometer indoor outdoor with Max/Min and Alert functions on both indoor and outdoor temperature and humidity. The MaxandMin data will update every 24hrs and you can press the MEM button to switch between and F. With audible alarm, you can set the maximum and minimum temp and humid alert values manually. It will ring when the value reaches at the point of pre-set max or min alarm values. Multiple ApplicationsGeevon digital indoor outdoor thermometer can be stand in the desk or hang on the wall as you like. You can place it in your bedroom, baby room, wine cellar, basement, garden, greenhouse, grow tent or office. The base station powered by 2 x AA Battery, and the remote sensor powered by 2 x AAA Battery(Not Included).