When Pan Am launched the first direct trans-continental flight between New

York and Moscow in 1959, the crew wore Rolex Oyster Constant-motion

GMT-Master watches. With a clear display of the time in two time zones, it

became the official watch of Pan Am, the most famous airline in the golden

age of civil aviation, and was widely accepted as a must-have chronometer

by pilots.
In 2013 Basel World Watch and Jewelry Expo, Rolex launched a new 904L

stainless steel oyster constant motion GMT-Master II watch, its rotating

outer ring for the first time using blue and black CERACHROM ceramic word

ring, blue on behalf of the day, black on behalf of the night.
The CERACHROM ceramic ring is a technical and aesthetic achievement of

Rolex. Using a patented technology developed by Rolex, the CERACHROM

ceramic ring is made of two different colored ceramic materials into a

single ceramic ring. This design echoes the traditional two-colour outer

ring of the first GMT-Master and GMT-Master II watches. CERACHROM ceramic

ring was invented in 2005. It has strong scratch and corrosion resistance

and does not fade even under ultraviolet light. Its surface is polished by

diamond and has excellent luster. A thin layer of platinum was filled with

rolex PVD (Physical vapor Deposition) plating technology within the 24-h

progressive scale of the character circle.
The Oyster case of the GMT-Master II, with a diameter of 40mm and water

resistance up to 100m (330ft), is an example of rugged elegance and

perfect proportion. The distinctive middle case is made of original 904L

stainless steel with strong corrosion resistance. The triangular pit

bottom cover is tightened by the rolex watchmaker with the brand’s own

special tools, so that the case is completely sealed. The upper chain

crown adopts the patented triple lock triple waterproof system, firmly

screwed to the case, and is protected by a middle case connected as one of

the crown shoulder. The mirror is made of scratch resistant blue crystal,

with a small convex lens at 3 points, which is more convenient to read the

date. The fully sealed Oyster case provides optimum protection for the

GMT-Master II’s highly accurate movement.
It adopts 3186 automatic chain machine movement completely developed by

Rolex, equipped with calendar window and second time zone display

function. Like all Rolex constant motion movements, the model 3186

movement has been certified by the Swiss Official Chronometer

Certification, which is awarded to a precision watch successfully tested

by the Swiss Chronometer Testing Center (COSC). The exquisite design of

this movement and the high quality of the production process make it has

unparalleled accuracy and reliability. The heart of the watch, the balance

swing component, is made from rolex’s patented blue PARACHROM wool and an

alloy cast exclusively by Rolex. This gossamer is not interfered by

magnetic field, it can still perform stably under temperature change, and

its seismic strength is up to 10 times that of traditional gossamer.
The watch is equipped with 904L stainless steel solid link oyster

watchband with oyster safety buckle, which can prevent the buckle from

opening accidentally; Rolex’s patented easy to adjust chain link extension

system is also installed on the buckle, making the strap easily extended

by about 5 mm, making it more comfortable to wear under all conditions.