Recorded in our Monte-Carlo solid 18K gold Rolex register, the Rolex GMT-Master II Guinness / Zombie Grey & Black Cerachrom 18K Yellow Gold Reference 126718GRNR unites authentic Geneva proportions (40.0 mm x 11.9 mm) with a certified 18K Yellow Gold Au750 mass of 225.8g. Every detail of the Hand-Finished Collector Dial with Solid 18K Gold Applied Hour Markers & Hands, Hand-Finished 18K Yellow Gold 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: Rolex GMT-Master II Guinness / Zombie Grey & Black Cerachrom 18K Yellow Gold — Official Reference 126718GRNR (SKU: MC-AU750-126718GRNR-W613).
• Precious Metal Alloy: 18K Yellow Gold Au750 with deep mechanical hallmarking and 5-axis Swiss CNC case finishing.
• Verified Reference Mass: 225.8g confirmed on our Monte-Carlo showroom Mettler-Toledo analytical balance.
• Mechanical Calibre: Rolex Manufacture Cal. 3285 - 70h Power Reserve operating at 28,800 vph (4 Hz) with 72-hour power reserve (+0.7 s/d, 297 deg).
• Sapphire Crystal & QC: Scratch-resistant sapphire crystal with double anti-reflective coating and 100m / 330 ft - Triplock Screw-Down water resistance.

Within the same Rolex horological silo, collectors also compare the Rolex Cosmograph Daytona Le Mans 100th Anniversary 18K Yellow Gold Ref. 126528LN (216.9g) and the Rolex Cosmograph Daytona Black Obsidian Dial & Sapphire Bezel 18K White Gold Ref. 126599TSA (216.9g).