The entire case of the RM 75-01—bezel, caseband and caseback—is cut and milled from solid blocks of sapphire. No external structures are used to support the assembled parts. Sapphire is known as a particularly scratch-resistant material with a hardness of 2,000 Vickers. Made of aluminium oxide (Al2O3) crystals, it is transparent thanks to its molecular composition.

The creation of coloured sapphire crystals requires precise incorporation of metal oxides into the sapphire crystal. The colour is determined by the types and quantities of oxides present within the crystal structure. Coloured sapphire is very sensitive to the heating process and crystal growth rate: if the right temperature conditions are not respected, it can affect the way oxides diffuse into the crystal lattice and lead to the uneven distribution of colours or undesired hues. Similarly, too fast a growth rate can lead to uneven colour and the generation of bubbles within the crystal.

Functions Hours, Minutes, Tourbillon

Mechanism Manual

POWER RESERVE Around 65 hours (±10%).

CALIBRE RM75-01

Manual winding flying tourbillon movement with hours

Strap / Material Rubber

Strap / Color white

Color Green