Recorded in our Monte-Carlo solid 18K gold Patek Philippe register, the Patek Philippe Nautilus Self-Winding Chronograph 40.5mm Blue Dial Reference 5980/1A-001 unites authentic Geneva proportions (40.5 mm x 12.2 mm) with a certified 904L Stainless Steel Custom Architecture mass of 155.4g. Every detail of the Hand-Finished Sunray Collector Dial with Hand-Finished Luminous Appliques & Hands, Brilliant-Cut VVS1 Diamond-Set Bezel with Anti-Reflective Scratch-Resistant Sapphire Crystal, and hallmarked clasp is verified under our Fischer XRF Au750 and Mettler-Toledo laboratory protocol.

5 Core Horological & Metallurgical Specifications:

• Registered Entity & Ref: Patek Philippe Nautilus Self-Winding Chronograph 40.5mm Blue Dial — Official Reference 5980/1A-001 (SKU: MC-CUST-5980/1A-001-W394).
• Precious Metal Alloy: 904L Stainless Steel Custom Architecture with deep mechanical hallmarking and 5-axis Swiss CNC case finishing.
• Verified Reference Mass: 155.4g confirmed on our Monte-Carlo showroom Mettler-Toledo analytical balance.
• Mechanical Calibre: Patek Philippe Cal. CH 28-520 C - 21K Gold Rotor operating at 28,800 vph (4 Hz) with 72-hour power reserve (+0.8 s/d, 303 deg).
• Sapphire Crystal & QC: Scratch-resistant sapphire crystal with double anti-reflective coating and 120m / 12 ATM water resistance.

Within the same Patek Philippe horological silo, collectors also compare the Patek Philippe Nautilus Self-Winding Custom SW Dial 22K Gold Rotor Ref. 5711/1A-011 (114.6g) and the Patek Philippe Nautilus Self-Winding Ref. 5711/1A-001 (114.6g).