Use the ItemHeight and ItemWidth properties to specify the size for the item in the group. By default, the ItemHeight property is 24 pixels. 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 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.