The Oyster Perpetual is celebrated for resistance to water and corrosion and is the most recognisable of the Perpetual collection. The models have managed to maintain their design throughout history, upholding the classic Rolex style. The original Oyster model was the first waterproof wristwatch in the world and was the innovator of the self-winding perpetual rotor. COSC tested. This 18ct Yellow gold model ref 6619 comes on a 18ct Yellow Gold bracelet.