IWC Schaffhausen adds a new chapter to its Ingenieur legacy with the release of the Ingenieur Perpetual Calendar 41 at Watches and Wonders Geneva 2025. This model marks the first time the signature stainless steel case of the Ingenieur, shaped by Gérald Genta’s design language, houses Kurt Klaus’ crown-operated perpetual calendar. With its 41-millimetre case, distinctive bezel secured by five functional screws, and a finely finished bracelet integrated through a middle-link system, the watch continues the evolution of a line that began with the Ingenieur SL in 1976. The dial features a blue “Grid” structure—an intricate lattice of lines and squares unique to this model—punctuated by three subdials that display the full calendar and a high-precision moon phase. The subdials are finished with azurage and sunray textures, each one pad-printed and laid out in a tri-compax arrangement that balances utility with aesthetic restraint. Luminous rhodium-plated hands and markers ensure readability across light conditions, while the moon phase, accurate to a single day in 577.5 years, reflects the calibre’s engineering focus. The perpetual calendar mechanism, fully synchronised and adjusted by the crown, requires no manual correction until the year 2100. Inside, the IWC 82600 calibre drives the watch with a Pellaton winding system enhanced by ceramic components. Designed for both efficiency and endurance, the bidirectional rotor winds the mainspring for up to 60 hours of reserve. Black and white zirconium oxide ceramic parts are used in critical wear points to improve long-term reliability. Beating at 4 Hz, the movement is visible through a sapphire case back, with decoration including Geneva stripes, blued screws, and circular graining.