The case of the Chronomètre FB 1R.6-1 is made of a new material: carburised stainless steel, a steel whose molecular structure has been reinforced by a thermochemical process. Its exceptional hardness of 1'200 Vickers on the surface makes it extremely resistant, particularly to corrosion.
Based on an unprecedented design, the barrel and fusee of the FB-T.FC.R calibre are reversed and suspended, thereby saving precious millimetres within the movement. They are connected by a chain comprising no less than 474 steel links for a total length of 280 mm. When the movement is fully wound, the tension on the chain is equivalent to three kilograms.
Visible through the openworking of the half-bridge on the case-back side, the power-reserve indication device consists of a mobile cone and a set of flat levers on the dial side. This highly sophisticated mechanism is the result of complex mathematical calculations that guarantee the concentric deployment of the balance-spring coils in all states of winding and unwinding.