Calatrava 8-Day White Gold / Blue

In Context

At 41 mm it is sized to the current mainstream: 40 mm is the median across every watch measured in this catalogue. At 10.52 mm thick it is about average for a modern wristwatch. The case back is open, so the movement is visible without taking the watch apart, and the sapphire crystal will resist everything short of deliberate abuse. Rated to 30 m, it is protected against rain and splashes and nothing beyond that.

The movement is hand-wound, so winding it becomes part of the day rather than something the watch does for you. 192 hours of reserve puts it well past a weekend — several days off the wrist and it is still going. At 28,800 vph the seconds hand advances 8 times a second.

5328G-001 stands on its own in this catalogue — no other reference here shares its base number. It pairs a blue gradient dial with a white gold case.

The manually wound caliber 31-505 8J PS IRM CI J integrates traditional watchmaking techniques with notable technical advancements. It features the Pulsomax® escapement, equipped with an escape wheel and lever made from Silinvar®, originally developed by the Patek Philippe Advanced Research program. Two series-coupled barrels provide a power reserve of eight days, maintaining consistent accuracy. A ninth "reserve" day, indicated in red on the curved power-reserve display at 12 o'clock, alerts the user to wind the movement. The caliber also includes an instantaneous day-date mechanism that jumps precisely at midnight. Patek Philippe Caliber Ref. 31-505 31-505 8J PS IRM CI J Instantaneous date by hand. Instantaneous day in an aperture. Power reserve indication. Small seconds. Diameter: 32 mm. Thickness: 5.05 mm. Number of parts: 256. Frequency: 28,800 semi-oscillations/hour (4 Hz). Power reserve: min. 192 hours (8 days). Escapement: Pulsomax®.