The celebrated Ingenieur model was developed by Albert Pellaton, IWC's technical director responsible for the creation of the firm's first automatic movement.The present example, from the reference series 866, was manufactured in 1971 and is powered by the firm’s in-house caliber 8541B.Reference 866 was introduced in 1967 and received several upgrades from its predecessor, most notably the larger diameter, the larger date indication and the presence of the hack feature.The present Ingenieur is also mounting the typical sunburst silver dial with applied IWC typical of that period.Considered one of the earliest "tool” watches, the Ingenieur model enjoys cult status amongst collectors thanks to its distinctive and timeless design.