Too right Genghis! I lost the transparent wind-vector window on my CRP-5 when sitting a nav paper many years ago...one of the retaining screws from the lower bezel fell out, followed shortly thereafter by the disc! Probably caused by the talcum powder used to help lubricate the wheel. Fortunately, a sympathetic invigilator recovered it for me and the screw had only fallen on the seat so disaster averted!