The Triplock Crown is a sophisticated winding crown system developed by Rolex, introduced in 1970. It is designed to enhance the waterproof capabilities of Rolex watches, particularly those intended for diving. The Triplock system features three sealed zones, providing superior protection against water ingress. Two of these O-ring gaskets are positioned within the tube, while the third is located under the winding crown itself. This design ensures that the watch remains watertight even when the crown is unscrewed. Initially debuting on the Sea-Dweller dive watch, the Triplock Crown was later incorporated into other Rolex models, including the Submariner, Sea-Dweller, and Deepsea, offering water resistance up to 3,900 meters. The Triplock Crown is identifiable by three dots under the Rolex coronet, with variations in dot size depending on the material of the watch case. This innovation underscores Rolex's commitment to precision engineering and durability, making it a hallmark feature of their professional dive watches.