By default the BorderGroupHeight property is 2 pixels. Use the BorderHeight property to specify the height of the control's border. Use the BorderWidth property to specify the width of the control's border. Use the BorderGroupHeight, BorderHeigth and BorderWidth properties to define the size of the groups inside the control's client area. The Left, Top, Width and Height properties determine the location of the group's list in client coordinates. The GroupHeight property specifies the height of the caption for all groups, in pixels. Use the ItemHeight property to specify height of the items in the group's list.