The shutters, with integrated blinds and ventilation slots, are attached to a standard sliding door mechanism; their lower rail has a guide groove held by a pin and roller. The sliding mechanism is mounted on a dovetail-shaped plank embedded in the concrete ceiling; it is concealed by the overlapping slate cladding of the upper floor. Two of the shutter panels in front of the wide French door slide over one another. Concealed internal locking mechanism.
