By default, the ItemHeight property is 24 pixels. Use the ItemHeight property to specify the height for all items in the group. The GroupHeight property specifies the height of the caption for all groups, in pixels. Use the Font property to specify the control's font. Use the SingleLine property to specify whether the caption of the items is displayed using single or multiple lines. Use the Caption property to specify the caption of the item. Use the SmallIcons property to specify the size of the icons being displayed. The AddGroup event notifies the control that a new groups is added.