This movement, invented and patented by Vincent Calabrese, shows the hour in a window which moves ahead a minute at a time. The hour changes at 12 o’clock, before the window sets off on another journey around the dial. Every three hours, the numbers are replaced by letters (M for midday or midnight, T for 3 o’clock, S for 6 o’clock, N for 9 o’clock), a very ingenious system that makes it easier to read the time as 6 and 9 could be confused as they move around. The case, with its transparent back, is water-resistant to 30 m and available in steel or 750 (18K) gold. The dial, either the brand’s traditional one or coloured, is protected by a slightly cambered sapphire crystal.