PATEK PHILIPPE Patek Philippe 5159G Perpetual Calendar Retrograde Grand Complication Watch | Excellent Condition, Watch Only Ref.5159G

Released in 2006, the Ref. 5159 perpetual calendar watch features the distinctive Calatrava round case styled after an Officer’s Watch. Inspired by vintage pocket watches used in wartime, which needed to be both precise and durable, these "Officer’s Watches" incorporate several unique features that set them apart from other Calatrava models.
In addition to a sapphire crystal case back, it also includes a hinged metal dust cover—a design element originally created to protect the watch face in military use. The straight lugs with rounded ends are secured by screw bars, further enhancing its military-inspired design.
Even among Patek Philippe's other grand complication watches, the Ref. 5159 stands out for its striking appearance and refined craftsmanship. One of its most unique features is the crown guard bridge that extends from the case back, giving it a truly one-of-a-kind look.
Beyond aesthetics, the Ref. 5159 boasts impressive technical merit. Its perpetual calendar mechanism includes two rare features: a centrally mounted sweeping second hand (unusual for an automatic perpetual calendar), and Patek Philippe’s patented retrograde date display, first introduced in 1986.
The day, month, and leap year are shown through individual windows on the dial, while the date is displayed in a retrograde arc above the moon phase sub-dial. The retrograde date hand gradually moves across the arc, and at the end of each month—whether 30 or 31 days—it instantly snaps back to "1". This display not only provides excellent legibility but also adds a dynamic and elegant character to the watch.