The Royal Oak concept watch series that was launched 12 years ago to celebrate the 30th anniversary of the first steel luxury watch continues exploring the world of materials with the titanium and white ceramic Royal Oak Concept GMT Tourbillon. The two-fold challenge is based on a combination of case materials that are ten times harder and longer to machine than steel, and on the complications of a Manufacture-made movement with a ten-day power reserve and featuring  bridges now made of platinum. Other high-tech materials also make their appearance, including the ultra-light aluminium on the inner bezel ring framing the dial, which is hardened by anodisation. The 85 parts of the tourbillon carriage weighing no more than half a gram call for two weeks of hand finishing (bevelling and polishing), and three days of assembly by an experienced watchmaker. Placed symmetrically opposite the tourbillon, the dual-time display is based on two discs showing the hours from 1 to 12 on the surface, and below that whether it is day (in white) or night (in black as on this visual). The 4 o’clock pusher enables quick and easy adjustment. Facing the AP logo appearing at noon, the H-N-R letters at 6 o’clock indicate the crown operating  mode : time adjustment, neutral or winding.