The iconic view settings classes (see UltraListView.ViewSettingsIcons, UltraListView.ViewSettingsTIles, UltraListView.ViewSettingsThumbnails properties) expose an ItemSize property. You didn't mention whether you were using a specific view but the list views (see UltraListView.ViewSettingsList, see UltraListView.ViewSettingsDetails) do not provide a way to set the item width. ViewSettingsList does, however, provide a way to set the column width via the ColumnWidth property.