By default, the VisibleParts property is 897 ( that's a OR combination of exLowerBackPart, exThumbPart, exUpperBackPart). The VisiblePart property specifies which part is visible and which part is hidden. By default, when a part becomes visible, the EnablePart property is automatically called, so it becomes enabled. Use the Background property to specify a visual appearance for a specified part of the control in a certain state. 

By default, the following parts are shown:

• exLowerBackPart ( the part between the start and the thumb part of the control )
• exThumbPart ( the thumb/slider part )
• exUpperBackPart ( the part between the thumb and the end part of the control )

The control fires the ClickPart event when the user clicks a part of the control. The ClickingPart event is fired continuously while the user keeps clicking the part of the control.