This Patek Philippe Reference 2545 is a rare Calatrava for the discerning collector with a keen eye for the history of Patek Philippe watches. On the surface, this watch looks very similar to the widely produced Reference 96, however there are a few small differences. First is the case size - at 32mm the 2545 is 1.5mm larger than the 96. Second is the screw down caseback, an improvement for water resistance. As few as 52 yellow gold reference 2545 examples are publicly known. Produced in 1961, this example is perhaps the latest known, with most known 2545s being made in the 1950s. This late production watch features a more modern printing on the Patek Philippe logo. This example was gifted in appreciation of 30 years of service by the Arabian American Oil Company (now ARAMCO).