Product features:Measure indoor and outdoor temperature and humidity, Celsius and Fahrenheit conversion.Maximum and minimum temperature and humidity memory function.You can view historical temperature and humidity data.Connect a maximum of 3 outdoor units (one outdoor unit in a conventional package)The rear shell of the main engine has two high magnetic magnets, which can be adsorbed on metal objects.A stand on the back of the unit allows you to stand in a horizontal position.High sensitivity touch key control, easy to operate.Comfort indicator, temperature and humidity trend indicator.HTN large HD non-viewing Angle color LCD display.With backlight, automatically turn off the backlight after 10 seconds without operation.The outdoor unit can be hung through a hanging hole or stand on a horizontal surface.Outdoor unit XP4 waterproof.Product parameters:Room temperature range: -4F to 158F (-20C to 70C).Outdoor temperature range: -40F to 158F (-40C to 70C).Humidity range: 20%-95%.Comfort display: Dry, comfortable, wet.Temperature display unit: C/F Optional (The default value is C).Temperature resolution: 0.1C/F.Humidity resolution: 1%.Refresh rate: 10 seconds.Error: Temperature plus minus 1 humidity plus minus 5%.Wireless range: 60 m /197 ft.RF Radio frequency: 433 MHz.Power supply: No. 7 battery (shipped without battery).