Base class from which all types of RibbonItem are derived.

Autodesk.AutoCAD.Customization.ElementBase
    Autodesk.AutoCAD.Customization.VersionableElement
        Autodesk.AutoCAD.Customization.CustomizationElement
            Autodesk.AutoCAD.Customization.RibbonItem
                Autodesk.AutoCAD.Customization.AbstractRibbonSubPanel
                Autodesk.AutoCAD.Customization.RibbonButton
                Autodesk.AutoCAD.Customization.RibbonCommandButton
                Autodesk.AutoCAD.Customization.RibbonDataBoundDropDown
                Autodesk.AutoCAD.Customization.RibbonPanelBreak
                Autodesk.AutoCAD.Customization.RibbonPanelSource
                Autodesk.AutoCAD.Customization.RibbonPanelSourceReference
                Autodesk.AutoCAD.Customization.RibbonSeparator
                Autodesk.AutoCAD.Customization.RibbonSplitButton
                Autodesk.AutoCAD.Customization.RibbonTabSelector
                Autodesk.AutoCAD.Customization.RibbonTabSource
                Autodesk.AutoCAD.Customization.RibbonToggleButton

Public abstract Class RibbonItem
Inherits CustomizationElement

public abstract class RibbonItem : CustomizationElement;