A Rolex solid eighteen carat yellow gold Oyster Perpetual model, reference 6618. This is an exceptional, and quite rare watch in a size that is no longer offered by the Crown. This is in itself is a very rare combination; smooth bezel, Oyster riveted bracelet and champagne dial.

The dial is stamped "T Swiss T" at the six o'clock position, meaning that it contains tritium luminous material. This material replaced the highly dangerous, and radioactive Radium in 1963. Just like radium, tritium was also radioactive; however, it came with a much lower level of radiation and a much shorter half-life. While tritium was exponentially safer than radium, it only had a half-life of twelve years. This meant that after just a few decades, only a tiny fraction of the initial luminescence would remain. Additionally, as tritium ages, the color changes, which creates often beautiful, and highly sought after patinas on the luminous markers on these older Rolex watches. Tritium was far from perfect, which lead Rolex to search for a better alternative, which happened in 1998 with the introduction of Luminova. The Tritium in this case is all original to the dial, is in perfect condition. The color is a very beautiful warm latté color, and the same for the hands. All of which respond the same under ultra violet light. Being from 1966, this represents one of the very early Tritium dials.

The watch is powered by a Rolex, Swiss made, twenty seven jewel automatic calibre 1161 movement. The Rolex Caliber 1161 was introduced during the 1960s as part of a new generation of automatic movements developed for Rolex’s smaller-sized watches. Produced by Aegler, Rolex’s long-standing movement manufacturing partner, the caliber was designed to deliver the same reliability and precision expected of the brand’s larger movements while fitting comfortably within ladies’ and midsize cases.

Featuring automatic winding, a robust construction, and Rolex’s characteristic focus on durability, the 1161 became a mainstay of the company’s elegant dress watches throughout the late 1960s and 1970s. It powered a variety of Oyster Perpetual and Datejust references, providing dependable everyday performance in a compact format.

While often overshadowed by Rolex’s larger and more widely discussed calibers, the 1161 represents an important chapter in the brand’s history. It reflects Rolex’s commitment to engineering excellence across every size category, ensuring that even its smallest watches were built to the same exacting standards that defined the company’s reputation.

The watch is fitted to its rare original solid eighteen carat yellow gold Rolex Oyster rivet bracelet with beautiful fully signed deployant buckle. This bracelet is a good size, and will fit most wrist sizes. There is a very little stretch to it, highlighting the lack of wear overall that this beautiful watch has seen in sixty years.

The watch was made circa toward the end of 1966 with serial number 1,443,XXX. The bracelet is date stamped on the clasp for "2 67", meaning the bracelet was made in the second quarter of 1967. It is so rare to find these bracelets. To find them still attached to the original watch is even more unusual today. The watch is in original condition, showing no signs of polishing to case. The case is very strong, with thick lugs and free from any damage. The original crisp hallmarks are present on the underside of the lugs.

The "OP" is perhaps one of the most beautiful models by Rolex, and examples like this in this size, 25mm, from this period are exceptionally hard to come by, and in this condition, even more so with this fabulous dial.