By default, the ImageSize property is 16 (pixels). The ImageSize property specifies the size of the icons the control displays. Use the Images method to attach a image list to the control. The DefaultItemHeight property specifies the height of the items.

The ImageSize property defines the size to display the following UI elements:

• any icon that a cell or column displays
• check-box or radio-buttons
• expand/collapse glyphs
• header's sorting or drop down-filter glyphs