Rolex Day-Date President 6611

Reference 6611 identifies the fluted-bezel model from the second Day-Date series, produced for a short period from approximately 1957 to 1959. This series is technically significant for the critical mechanical upgrades it introduced over the inaugural 65xx models. It is powered by an improved version of the Caliber 1055, which is historically significant for its implementation of a free-sprung balance with Micro-Stella regulation. This advanced regulating system provided superior isochronism and allowed the movement to be certified to the newly established, stricter ‘Superlative Chronometer’ standards, a text that first appeared on the dials of this series. The 36mm Oyster case is fitted with an acrylic crystal and a non-quickset day and date complication.