The Rolex Datejust fluted bezel is a mark of distinction. Originally, the fluting of the Oyster bezel had a functional purpose: it served to screw the bezel onto the case helping to ensure the waterproofness of the watch. It was therefore identical to the fluting on the case back, which was also screwed onto the case for waterproofness, using specific Rolex tools. Over time, the fluting became an aesthetic element, a genuine Rolex signature feature. Today the fluted bezel is a mark of distinction, in gold on this Lady-Datejust. The sunray finish creates delicate light reflections on many dials in the Oyster Perpetual collection. It is obtained using masterful brushing techniques that create grooves running outwards from the centre of the dial.