By default, the OverviewZoomUnit property is 42 pixels. The OverviewZoomUnit property indicates the width in pixels of the zooming unit. Use the OverviewVisible property to show or hide the control's overview area. Use the AllowOverviewZoom property to show or hide the zooming scale on the overview area. The zooming scale displays the list of visible units. A visible unit is an unit whose Label property is not empty. So, the Label property indicates the zooming units in the zoom scale. The OverviewZoomCaption property indicates the caption being displayed in each zooming unit. The LabelToolTip retrieves or sets a value that indicates the predefined format of the level's tooltip for a specified unit.

The zooming scale may be displayed on the overview area only if:

• AllowOverviewZoom property is not exDisableZoom
• OverviewVisible property is True
• OverviewHeight property is greater than 0
• there are at least two visible units, that has the Label property not empty.