The Greubel Forsey Grande Sonnerie commands respect. A

few quantitative elements give some idea of the scale of this undertaking: 11

years of research and development, 935 components assembled inside a case that

measures 43.5 mm in diameter and 16.13 mm high, 11 security functions and two

patents for a timepiece that offers grande and petite sonneries on cathedral

gongs, an on-demand minute repeater, and a 24-seconds inclined tourbillon

escapement. A dual power-reserve display, for the striking mechanism and for

the timekeeping function, completes the picture. Note that the striking mechanism

is automatically wound by rotor whereas the timekeeping mechanism is manually

wound. This is the most complex watch ever by Greubel Forsey, hence between three

and five only will be made each year.