Gentlemen: On my SDH,at the bottom of my headlight,at the 6 o'clock position,there is a little hole or window which has a plug covering it from the inside or back of the assembly.What is that little window used for??I looked at my SM but can't find anything in there pertaining to that little window. It must be there for some reason,but obviously not used on my model.Just curious! Thank you!! Dummy Dave!!!