Model case Oyster, 44 mm, yellow gold Oyster architecture Monobloc middle case, screw-down case back and winding crown. Rolex Ringlock System case architecture with Helium escape valve Diameter 44 mm Material 18 ct yellow gold Bezel Unidirectional rotatable 60-minute graduated, scratch-resistant Cerachrom insert in blue ceramic, numerals and graduations coated in gold Winding crown Screw-down, Triplock triple waterproofness system Crystal Domed, 5.5 mm-thick scratch-resistant sapphire Water resistance Waterproof to 3,900 metres / 12,800 feet, helium escape valve Bracelet Oyster, three-piece solid links Material 18 ct yellow gold Clasp Folding Oysterlock safety clasp with Rolex Glidelock extension system Dial Blue Details Highly legible Chromalight display with long-lasting blue luminescence