PATEK PHILIPPE PERPETUAL CALENDAR CHRONOGRAPH Ref. 5204R-001
The split-seconds Perpetual Calendar chronograph is one of the three most difficult complications to master, alongside the tourbillon and the minute repeater. It takes a highly sophisticated mechanism to control the two chronograph hands, one of which may be stopped to measure an intermediate or lap time or retain a reference time while the other continues its course unaffected, even by fractions of a second. When released again, the split-seconds hand instantly catches up with the primary hand and the two stacked hands move on together.
40.2 mm rose gold material. Interchangeable full back and sapphire-crystal case back. Dial: silvery opaline, applied gold hour markers with luminescent coating. 18K gold dial plate. Brown leather strap with square scales, hand-stitched, shiny chocolate brown, fold-over clasp. Manually wound mechanical movement. Caliber CHR 29‑535 PS Q. Day, month, leap year and day/night indication in apertures. Date by hand. Seconds subdial. Water resistant to 30 m.