The anatomy of a Rolex


Oyster case

Oyster case

The world is your oyster

This is our Oyster case, the world’s first waterproof wristwatch case, conceived by Rolex in 1926 and patented. A one-of-a-kind feature, which holds within it an intricate world of cogs and minutely crafted parts. Made of some of the most refined alloys, the Oyster case is incomparably resistant to all sorts of external aggressions.

Yet no object so hermetic, so immovable, has ever opened the door to so many possibilities. With its original patented design consisting of a bezel, a case back and a winding crown screwed down against the middle case, it profoundly changed the course of watchmaking history and set new standards of waterproofness for all wristwatches. To this day, the Oyster case continues to protect our watches and our movements within them. It stands as undeniable proof of our constant quest for reliability.

Oyster Case
Cyclops lens

Cyclops Lens

At a single glance

This is our Cyclops lens. Introduced in 1953 to ease the legibility of the date, this curved lens set on the crystal at 3 o’clock, above the window, has become one of our most emblematic features.

At first sight, it may not seem very technical. Yet it has been improved ceaselessly, from its composition to its shape, to achieve utmost efficiency. Today, it is made from a virtually scratchproof sapphire crystal and benefits from a double anti-reflective coating. This lens immediately catches the eye. As it should, bringing the date into clear focus. Easily. At a single glance.

Cyclop lens
Crown guard

Crown guard

Close protection

This is our crown guard. Designed to protect the winding crown, it was introduced in 1959 on the Submariner and GMT-Master before equipping most of our Professional watches.

Stamped as an integral part of the middle case, it elegantly extends the case sides to the tip of the crown. Its unique design blends perfectly with each model’s curves, ensuring harmonious continuity of the case. Close protection requires two inseparable qualities: a reassuring presence and an ability to remain inconspicuous.

Crown guard


The power of three

This is our Triplock winding crown. It is equipped with an innovative system we introduced in 1970 on the Sea-Dweller: a “triple lock” that creates three sealed zones. As early as 1926, our Oyster case came with a screw-down crown to prevent what “can” happen: water, sweat or dust entering the watch.

Then, in 1954, we conceived the Twinlock winding crown and its added waterproof barrier to counter what “could” happen: for instance, a rare incident which could compromise a gasket during a dive. As for our Triplock winding crown, it was created to face what purely “can’t” happen: the crown somehow unscrewing itself at 11,000 meters (36,090 feet) below the surface… Hence, whatever the depth, we’ve sealed our watches from the impossible.

Triplock lens
Helium Escape valve

Helium escape valve

There and back again

This is our helium escape valve. Patented in 1967, it protects our watches designed for extreme diving. Rolex invented this valve so that the helium used for dives in hyperbaric tanks could be released during decompression.

The valve triggers systematically when the pressure inside the watchcase is too high. Thus, the hermeticity of the watch is never compromised. Indispensable to human beings when saturation-diving, helium is a noble gas, but an intrusive one. Its atoms penetrate anything. Even watchcases, through its seals, no matter how airtight they may be. And if they are not dealt with swiftly enough during the ascent, the internal pressure can cause the glass to pop, therefore affecting the integrity of the case, and impacting the performance of the movement. That is why we invented this self-regulating system, which today consists of a hermetic cylinder, a piston, a seal and a spring. Because to us, when it comes to depth, the true feat lies not only in the descent, but in the journey back to the surface.

Helium escape valve
Ringlock system

Ringlock system

Under pressure

Our Ringlock system, introduced in 2008, equips our diving watches designed for extreme depths. It is a unique and patented case structure which can withstand the colossal pressure of the abyss. In turn, let us dive into its distinctive three-layer architecture.

First comes a slightly domed sapphire crystal no thicker than a few millimetres. Deeper, we encounter a highly resistant compression ring made of nitrogen-enriched steel. Then, deeper still is found a RLX titanium case-back. In the wake of our original Oyster case, the first milestone in our mastery of waterproofness, the Ringlock system is the expression of a conviction and an ambition constantly reaffirmed. To us, as unforgiving as it is, pressure is a catalyst in our quest for perfect hermeticity, pushing us to take our mastery of waterproofness even further. And if we’ve managed to make it an ally, it is to enable you to reach for new horizons.

Ringlock system

Rolex Watchmaking Know-how

Excellence in the making