Deep Commitment The Rolex Sea-Dweller is built for the extremes of deep-sea diving. With its helium escape valve and exceptional water resistance, it represents the pinnacle of Rolexs professional dive watch engineering. Engineered for Depth This 2019 reference features a 43mm Oystersteel case with a black dial and rotatable bezel. At its core is the calibre 3235 automatic movement, offering approximately 70 hours of power reserve. The Oyster bracelet is equipped with a Fliplock extension, Rolex Glidelock system, and Oysterlock claspdelivering uncompromising performance at any depth.