5990/1A - NAUTILUS
SELF-WINDING
The Ref. 5990/1A-011 Nautilus Travel Time chronograph is one of Patek Philippe’s rare steel watches. It features a new blue dial with a ray sunburst dial and a delicate black gradation to the periphery.
The self-winding caliber CH 28-520 C FUS movement combines three convenient and user-friendly complications: a flyback chronograph, a Travel Time function (two time zones with two separate hour hands; the skeletonized hand shows home time) and an analog date at 12 o'clock which is synchronized with local time.
WATCH
Self-winding mechanical movement. Caliber CH 28‑520 C FUS. Flyback chronograph. Central chronograph hand. 60-minute counter. Two time zones: local and home time indication. Day/night indication for local time and home time in apertures. Date coupled with local time by hand.
DIAL
Sunburst blue with black-gradient rim, horizontally embossed, gold applied hour markers with luminescent coating.
CASE
Steel. Case diameter (10 - 4 o’clock): 40.5 mm. Height: 12.53 mm. Water-resistant to 30 m. Screw-down crown. Sapphire crystal case back.
BRACELET
Steel. Patented fold-over clasp with lockable adjustment system.

CH 28-520 C FUS
SELF-WINDING
Flyback chronograph. Central chronograph hand. 60-minute counter. Two time zones: local and home time indication. Day/night indication for local time and home time in apertures. Date coupled with local time by hand. Diameter: 31 mm. Thickness: 6.95 mm. Number of parts: 370. Jewels: 34. Power reserve: min. 45 hours - max. 55 hours. Winding rotor: 21K gold central rotor. Balance: Gyromax®. Frequency: 28,800 semi-oscillations per hour (4 Hz). Balance spring: Spiromax®. Hallmark: Patek Philippe Seal.