This IWC Schaffhausen pocket movement dates to 1916 and carries the large-format “Jumbo” presence typical of early 20th-century watchmaking. Its architecture and finishing reflect a period when movements were built for robustness and clear legibility, with thoughtful mechanical layout and attention to detail. The Cal. 66 movement speaks to IWC’s technical tradition in precise, serviceable calibres from that era. For the contemporary collector, such a movement offers a direct, tactile connection to classic watch construction and the techniques that shaped modern mechanical timekeeping.