Triplock
Screw-down winding crown with a triple waterproofness system developed by Rolex to enhance the water resistance of its divers’ watches, which is also now fitted on a number of Professional models. The Triplock system is identified by three dots (with sizes that differ depending on the material of the crown) below the Rolex emblem on the face of the winding crown. The Triplock system ensures waterproofness to a depth ranging from 100 to 3,900 metres (300 to 12,800 feet) depending on the case.
Twinlock
Screw-down winding crown with a double waterproofness system developed by Rolex. It ensures waterproofness to a depth of 100 metres (330 feet). Depending on the material of the crown, the Twinlock system is identified by one dot, two dots or a line below the Rolex emblem on the face of the winding crown.
