Wireless technology with included weather-resistant temperature & humidity sensor; Up to 330ft (100m) transmission range Displays indoor and outdoor temperature (°F/°C) & humidity (%RH) with HI/LO records and time with date stamp 12 hour digital time with calendar view Interchangeable Temp or Humidity views; Sensor strength and low battery indicator icons Battery operated; requires 2 AAA alkaline batteries for display; requires 2 AAA for sensor (batteries not included)