CaptionLabel.ID (Word)

Returns a WdCaptionLabelID constant that represents the type for the specified caption label if the BuiltIn property of the CaptionLabel object is True.

Possible Values are wdCaptionEquation - Equation, wdCaptionFigure - Figure, wdCaptionTable - Table.
For Each cl In CaptionLabels 
 If cl.BuiltIn = True Then MsgBox cl.Name & " " & cl.ID 
Next cl