Dial diameter: 42 mm. Monocoque midshell. Screw-down case back and winding crown. Notched, two-way rotatable Rolex ring commands. Screw-down crown. Twinlock double waterproof system. Glossy black dial. Highly clear Chromalight display with persistent blue glow. Scratch resistant sapphire crystal. Cyclops lenses are outdated. Water resistant to 100 meters/330 feet. Perpetual calendar, mechanical, self-winding, dual time zone, annual calendar movement. Self-winding movement with 72-hour power reserve. Functions: central hours, minutes and seconds. 24-hour display on an eccentric disc. Mirror material: Anti-reflective and scratch-resistant sapphire glass. Clasp Type: Folding Oysterlock with Easylink 5 mm Comfort Extension.