A model that may be entirely personalised, from the case to dial and including the strap and even the celestial chart, the Portuguese Sidérale Scafusia is an eminently striking model both in terms of its aesthetics and the complexity of its mechanism comprising over 500 parts. This impressive demonstration of strength by IWC comprises a gigantic constant-force tourbillon with a titanium carriage, as well as an innovative perpetual calendar indicating the number of days elapsed since the start of the year, and a sidereal time display showing the exact position of 500 stars and milky ways from a position on earth chosen by the wearer of the model – and thus by nature unique. Moreover, the astronomic module on the back also indicates sunrise and sunrise times in both summer and winter, and a clever set of patented polarising filters transforms the dial colour at dawn and at dusk: the background is blue by day (while specifying the position of the stars when the sun is shining) and grey by night. Each celestial chart is meticulously reproduced by cosmologist Ben Moore, director of the Institute for Theoretical Physics at the University of Zurich. This achievement represents the culmination of intense cooperation between the professor and the IWC teams, along with ten years of R&D.