Use this property to turn on or off the checkboxes for file and folder selection. The checkboxes will only work, if a TJamShellLink has been assigned to the ShellLink property of this component. It will automatically synchronize the selection state of the items in multiple shell controls linked together with this TJamShellLink.  

To query the current selection state for an item, you can use the GetItemSelectionState method of this component. To access or modify the list of selected files and folders use the TJamShellLink.SelectionList property of the connected TJamShellLink.  

ShellControls.TJamShellList