limiting to the invention and can be a single glass or plastic sheet or a pair of glass and plastic sheets and combinations thereof laminated together by a interlayer material as is known in the art e g as described in u s patent application publication 2007 0002422a1 when the sheets are made of glass the glass is preferably chemically tempered heat tempered or heat strengthen the materials of the sheets and the number of sheets of the structural ply 48 is not limiting to the invention the inboard protective overly sheet 43 is not limiting to the invention and can be any of the types used in the art e g a plastic sheet to protect the underlying pane 28 from surface scratches caused by passenger curiosity cleaning solutions and or abrasive cleaning materials in the preferred practice of the invention the pane 28 is an electro chromic device or window 28 having the medium 31 changing percent of light transmission as a function of changes in voltage applied to the medium the invention is not limited to the construction of the electro chromic window and any of the types known in the art e g u s pat nos 5 215 821 6 471 360 and 6 783 099 and u s patent application publication 2007 0002422a1 can be used in the practice of the invention the invention also contemplates the pane 28 being a photo chromic device having a pair of glass sheets spaced from one another and a medium between the sheets that changes percent of light transmission as a function.