This Rolex Submariner with its 40 mm Oystersteel case with unidirectional rotatable bezel 60-minute graduated, scratch-resistant Cerachrom insert in ceramic, numerals and graduations coated in platinum. The bezel with its unidirectional rotatable abilities is engraved with 60-minute graduations allowing the diver to safely and accurately monitor diving time and decompression stops. The black dial luminescent Chromalight display is an innovation that improved visibility in dark environments, an essential feature for divers. Hour markers in simple shapes – triangles, circles, rectangles – and broad hour and minute hands enable instant and reliable reading to prevent any risk of confusion underwater this is protected by a scratch resistant sapphire crystal. Screw down case back and winding crown. The power behind this Rolex is the Calibre 3135 automatic movement it offers functions that include centre hour, minute and seconds hands and stop seconds for precise time setting. With a 48-hour power reserve and is water resistant at 300 meters / 1000 feet. Complimented by an Oyster, flat three-piece link bracelet in Oystersteel and secured with a folding Oysterlock safety clasp.