The Nautilus reference 5980/1A-001 is the original Nautilus Chronograph as introduced in 2006 in celebration of the 30th anniversary of Patek's iconic sports watch. It features a stainless steel case of 40.5mm and a matching, integrated bracelet. The dial is blue; a black and a white dial would be introduced a few years later.
Movement
Chronograph with 60-minute and 12-hour mono-counter. Date. Diameter: 30 mm. Height: 6.63 mm. Parts: 308. Bridges: 13. Jewels: 35. Power reserve: Min. 45 hours - max. 55 hours. Central rotor in 21K gold, unidirectional winding. Balance: Gyromax®. Vibrations/hour: 28 800 (4 Hz). Balance spring: Spiromax®. Hallmark: Patek Philippe Seal.