Recorded in our Monte-Carlo solid 18K gold Patek Philippe register, the Patek Philippe Nautilus Moonphase & Power Reserve Hand-Chamfered Bevel Spec Reference 5712A unites authentic Geneva proportions (40.0 mm x 8.52 mm) with a certified 904L Stainless Steel Custom Architecture mass of 116.3g. Every detail of the Hand-Finished Sunray Collector Dial with Hand-Finished Luminous Appliques & Hands, Satin-Brushed Rounded Octagonal Bezel with Mirror-Polished Chamfered Bevels 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 Moonphase & Power Reserve Hand-Chamfered Bevel Spec — Official Reference 5712A (SKU: MC-CUST-5712A-W771).
• Precious Metal Alloy: 904L Stainless Steel Custom Architecture with deep mechanical hallmarking and 5-axis Swiss CNC case finishing.
• Verified Reference Mass: 116.3g confirmed on our Monte-Carlo showroom Mettler-Toledo analytical balance.
• Mechanical Calibre: Patek Philippe Cal. 240 PS IRM C LU - 22K Gold Micro-Rotor operating at 28,800 vph (4 Hz) with 72-hour power reserve (+0.5 s/d, 302 deg).
• Sapphire Crystal & QC: Scratch-resistant sapphire crystal with double anti-reflective coating and 60m / 6 ATM water resistance.

Within the same Patek Philippe horological silo, collectors also compare the Patek Philippe Aquanaut Extra-Large Self-Winding Geneva Atelier Spec Ref. 5167A (79.6g) and the Patek Philippe Aquanaut Extra-Large Self-Winding Ref. 5167A-012 (79.8g).