The oscillator, the true heart of the Rolex Oyster Perpetual GMT-Master II Replica Watch, has a blue Parachrom hairspring patented and manufactured by Rolex in an exclusive alloy of niobium and zirconium.The GMT-Master II is equipped with calibre 3186, a self-winding mechanical movement with a second time zone function and date display entirely developed and manufactured by Rolex. Insensitive to magnetic fields, the Parachrom hairspring offers great stability when exposed to temperature variations and remains up to 10 times more precise in case of shocks than a traditional hairspring. Like all Rolex Perpetual movements, the 3186 is a certified Swiss chronometer, a designation reserved for high-precision watches that have successfully passed the Swiss Official Chronometer Testing Institute (COSC) tests. Its design and quality manufacture ensure peerless precision and reliability.
The fluted case back is hermetically screwed down with a special tool exclusive to Rolex watchmakers.The GMT-Master II’s 40 mm Oyster case, guaranteed water-proof to a depth of 100 metres (330 feet), is a paragon of robustness, proportion and elegance. The crystal, with a Cyclops lens at 3 o’clock for easy reading of the date, is made of virtually scratchproof sapphire. The waterproof Oyster case provides optimal protection for the GMT-Master II Replica high-precision movement. The winding crown, fitted with the patented Triplock triple waterproofness system, screws down securely against the case. The characteristically shaped middle case is crafted from a solid block of 18 ct white gold, cast by Rolex in its own foundry. It is protected by a crown guard that is an integral part of the middle case.
An exceptional achievement on two counts, the innovation consists of creating a red ceramic disc – a colour that, in itself, is extremely difficult to obtain – and then locally modifying the chemical composition of each grain, right to the core of the ceramic, to change the red into blue over only half the insert with a perfectly clear demarcation between the two colours. This insert echoes the traditional two-colour bezel of the original GMT-Master and GMT-Master II models. The Rolex Cerachrom bezel inserts, introduced in 2005, have the advantage of being virtually scratch-resistant, highly corrosion-resistant, and their colour is unaffected by ultraviolet rays.A technological and aesthetic feat, the new red and blue Cerachrom bezel insert is obtained via a unique manufacturing process developed and patented by Rolex, which enables the production of a single-piece, bulk-coloured ceramic component in two distinct Rolex Replica Watch. Their diamond-polished surface offers a long-lasting lustre.