The innovative process developed by Rolex to obtain the unique twocolour Cerachrom bezel inserts for the GMT-Master II consists in changing the colour of the ceramic on one half of the insert. The change of colour is achieved by impregnating half of the insert with an aqueous solution containing various chemical compounds. The solution is added before the sintering process, during which the ceramic acquires its mechanical resistance properties as well as its colour or colours. In the course of this sintering, the ceramic densifies and the added compounds react with the basic elements of the Cerachrom insert, which alters the initial colour on one half of the insert. Since it is manufactured in a single piece, the insert acquires mechanical resistance properties like the rest of the watch.
The Chromalight display uses an innovative luminescent material, which emits a blue glow, on the hands, hour markers and other display elements of the watches for optimal and long-lasting legibility.
The screw-down winding crown and the case with screw-down back together make up the Oyster’s exceptional waterproof design, patented in 1926, allowing the wearer to adjust the essential functions of the watch, or to wind it, by interacting directly with the movement.