The Virtual Fence / Geo-Fence feature lets you create a selected area on the monitor screen.
 

Once the fence area is set, the system can help detect movement in relation to that area. Depending on your setting, the monitor can alert you when your baby moves into the area or moves out of the area. This is helpful when you want extra awareness during playtime, rest time, or when using the monitor outside the car.
 

You can set up this feature through Fence Calibration on the monitor.