Rolex Oyster Perpetual Med Blue 31mm 277200Overview The Rolex Oyster Perpetual 31 reference 277200 is the definitive modern expression of the watch that founded a global legacy. Built upon the twin pillars of Rolexs identitythe waterproof Oyster case and the self winding Perpetual movementthis model represents the quintessential "everything watch." While the 31mm proportions offer a feminine, jewelry like elegance, the watch retains the robust, tool watch DNA that has defined Rolex since the