Patek Philippe Split-Seconds Monopusher Chronograph with perpetual calendar ref. 5373P-001


Patek Philippe Split-Seconds Monopusher Chronograph with perpetual calendar ref. 5373P-001

Split-Seconds Monopusher Chronograph with perpetual calendar
ref. 5373P-001

A highly exclusive timepiece for left-handers and connoisseurs of rarities
La Cote des Montres - November 3rd, 2022

Patek Philippe is extending the broad palette of its chronographs and grand complications with the addition of a new timepiece literally made for the right-hand wrists of left-handers. With this goal in mind, the manufacture reinterpreted one of its most refined timepieces: the Ref. 5372 Split-Seconds Monopusher Chronograph. The new Ref. 5373P-001 features a platinum case and modern looks that emphasize its sporty and contemporary style dial. This new model will be produced in small series, appealing especially to left-handers among the connoisseurs of elaborate mechanical movements and passionate watch collectors.

In 2005, Patek Philippe leveraged its know-how in the field of short-time measurement by launching a new initiative: the manufacture developed a complete series of chronograph movements with and without additional functions. All of them were designed and produced in-house. The starting signal was given by the manually wound caliber CHR 27-525 PS, the world’s thinnest column-wheel-controlled split-seconds chronograph movement. The caliber CHR 27-525 PS Q launched in 2010 (with the same base movement plus an extremely thin calendar module) has a height of only 7.3 mm. It is the thinnest split-seconds chronograph movement with perpetual calendar ever produced by the manufacture. Since 2017, this exceptional caliber has been crafted in very small numbers in line with venerable watchmaking traditions. It ticks in a platinum watch with a blue sunburst dial (Ref. 5372P-001) or a rose gilt dial with a vertical satin finish (Ref. 5372P-010).

Inspired by a one-of-a-kind piece sold by Patek Philippe in 1927, a custom-made cushion-shaped split- seconds chronograph (movement No. 198 012), the manufacture has now converted the Ref. 5372 into a new version for left-handers – a genuine debut in the recent history of the maison in Geneva. The exclusive Ref. 5373P-001 combines a split-seconds chronograph with one of the most elaborate functions – the perpetual calendar which stands emblematically for the grand complications of Patek Philippe.


Inverted displays
and operating elements


With a diameter of 38.3 mm, the platinum case has the same size as the Ref. 5372 but its crown (with an integrated chronograph monopusher) is at 9 o’clock and the split-seconds pusher occupies an unusual position at 8 o’clock. It preserves its timeless elegance with the polished, concave bezel that creates the perfect transition to the slightly domed sapphire-crystal back, the recessed and satin-finished case flanks, and the delicately curved strap lugs that merge with the bars almost seamlessly.

The indications (counters and apertures) of the dial are rotated by 180°: the analog date at 12 o’clock, the subsidiary seconds at 3 o’clock, the moon phases at 6 o’clock and the 60-minute counter at 9 o’clock, complemented by the aperture displays for the day of the week and the month as well as the leap year cycle at 10:30 and the day/night indicator at 1:30. Patek Philippe has also reworked the aesthetic appeal of the dial, endowing it with a charcoal-colored aspect and a vertical satin-finish; it is ingeniously animated by a black gradation to the periphery and the snailed ebony-black subsidiary dials.

The indication of the time is based on applied Arabic numerals and faceted Dauphine hour and minute hands in white gold. The moon-phase display is extremely precise: it deviates from the actual lunar cycle by just one day every 122 years. For crisp legibility, the three chronograph hands from the center – chronograph and split-seconds hands as well as the 60-minute counter hand at 9 o’clock – are varnished red. The three chronograph commands (Start, Stop, and Reset) are selected with the monopusher in the crown at 9 o’clock. Stopping lap times with the split-seconds hand (rattrapante) is handled with the rectangular pusher at 8 o’clock.

A sapphire-crystal display back (interchangeable with the solid-platinum back delivered with the watch) reveals the fantastic architecture of the caliber CHR 27-525 PS Q movement with its two column wheels that bear two polished caps in the typical Patek Philippe style. The bridges, decorated with Geneva striping, are carefully chamfered and the edges are polished. A focus is also on the elegance of the form parts and the bridges à l’ancienne. Their acute internal angles can only be completed by hand, which calls for considerable dexterity and many years of experience.

The sporty looks and modern attitude of the dial also applies to the black calfskin strap with an embossed textile texture and red contrast seams. It is secured with a platinum fold-over clasp.

Like all of Patek Philippe’s platinum watches, the new Ref. 5373P-001 features a brilliant cut diamond in the caseband. As an exception for left-handers, it is set at 12 o’clock in this timepiece.

From now on, this watch is the only remaining model with the caliber CHR 27-525 PS Q movement that was formerly available in the Ref. 5372P-001 and 5372P-010; both models have been retired from the collection.


An illustrious predecessor


Crafted in 1925-1926 on request for a left-handed customer and sold in 1927, this split-seconds chronograph with a cushion case in 18K yellow gold (34 x 34 mm) and movement No. 198‘012 (diameter 13 lignes) stood out with its unusual arrangement of operating elements and displays. The case and the movement were rotated by 180° with the chronograph pusher at 9 o’clock instead of 3 o’clock and the split-seconds pusher at 8 o’clock instead 2 o’clock. The silver dial with black Brequet numerals was reconfigured to reposition the 30-minute chronograph counter from 3 to 9 o’clock and the subsidiary seconds from 9 to 3 o’clock. The uncommon shape of the chronograph and split-seconds hand with counterweights stands out as well.

Patek Philippe
Split-Seconds Monopusher Chronograph
with perpetual calendar

Technical data

Reference : 5373P-001
Movement :Caliber CHR 27-525 PS Q
Manually wound mechanical movement
Split-seconds chronograph with column wheel
Chronograph and split-seconds hand
60-minute counter, and subsidiary seconds
Perpetual calendar with day, month, leap-year cycle and day/night indication in apertures
Analog date
Moon phases
Diameter : 27.3 mm
Hauteur :7.3 mm
Base movement: 5.25 mm
Perpetual calendar: 2.05 mm
Components: 476
Jewels :31
Power reserve :Min. 38 hours – max. 48 hours (with the chronograph uncoupled)
Balance :Gyromax®
Frequency :21,600 semi-oscillations per hour (3 Hz)
Balance spring :Breguet
Crown functions : 2-position crown:
  • Pushed in: To wind the watch
  • Pulled out: To set the time and stop the seconds hand
Pushers :
  • Pusher in the crown at 9 o'clock to start, stop, and reset chronograph
  • Pusher at 8 o'clock to start and stop the split-seconds hand
Displays :Center hour and minute hands
Sweep chronograph and split-seconds hands
Subsidiary dials:
  • Subsidiary seconds at 3 o'clock
  • 60-minute counter at 9 o'clock
  • Date at 12 o'clock
Display apertures :
  • Day of week at 3 o'clock
  • Month at 9 o'clock
  • Day/night at 1:30
  • Leap-year cycle at 10:30
  • Moon phases at 6 o’clock
Correctors :
  • Day of week between 2 and 3 o’clock
  • Month between 6 and 7 o’clock
  • Moon phase between 4 and 5 o’clock
  • Date at 6 o'clock
Delivered with correction stylus in ebony and 18K white gold
Hallmark :Patek Philippe Seal
Case :950 platinum
Delivered with solid platinum back and interchangeable sapphire-crystal display back
Water-resistant :30 meters (3 bar)
Diameter:38.3 mm
Height :12.93 mm
Width between lugs :20 mm
Dial :Dial in 18K gold
Charcoal-colored with black gradation
Vertical satin finish
Applied Arabic numerals in 18K white gold
Faceted Dauphine hour and minute hands in 18K white gold
Arrow-shaped chronograph and split-seconds hands in Pfinodal, lacquered red, counterweighted
Snailed ebony-black subsidiary dials:
  • Subsidiary seconds at 3 o'clock: White-gold baton hands, lacquered white
  • 60-minute hand at 9 o'clock, white-gold baton hand, lacquered red
  • Date hand at 12 o'clock: White-gold baton hands, lacquered white
Bracelet :Black calfskin with embossed textile texture and contrasted red stitching
Buckle :Platinum fold-over clasp