The Panel class contains two ToolPanel reference, one is on the above of another. It describes a Dashboard panel.

Autodesk.AutoCAD.Customization.ElementBase
    Autodesk.AutoCAD.Customization.VersionableElement
        Autodesk.AutoCAD.Customization.CustomizationElement
        Autodesk.AutoCAD.Customization.IImageContainer
            Autodesk.AutoCAD.Customization.Panel

Public Class Panel
Inherits CustomizationElement
Inherits IImageContainer

public class Panel : CustomizationElement, IImageContainer;