Surface Area Sensor command bar

Positive Area: Specifies that you want to track the positive area of the surface in the sensor. A positive surface area sensor monitors the total area of the surface. Any "holes" or internal boundaries in a surface are not included in the surface area calculation.
Negative Area: Specifies that you want to track the negative area of the surface in the sensor. A negative surface area sensor monitors the "holes" or internal boundaries in a surface.
Select: Defines the type of faces you can select. You can specify that you want to select individual faces or a chain of faces.
Deselect (x): Clears the selection.
Accept (check mark): Accepts the selected faces.