The Rolex Sea-Dweller reference number 126600 is a professional diver's watch crafted from Oystersteel. It features a unidirectional rotating bezel with a scratch-resistant black Cerachrom insert.The dial is black and has large Chromalight hands and hour markers that glow blue for easy reading in low-light conditions.The watch is water-resistant to an impressive 4,000 feet (1,220 meters) and also has a helium escape valve. A self-winding mechanical movement provides power for approximately 70 hours.