IWC Schaffhausen 98

Caliber 98 is a manual-winding movement manufactured by IWC Schaffhausen, launched in 1945 and discontinued in 1958. It derives from the pocket watch Caliber 68 and features 27 ruby bearings, a slotted bimetallic balance, and swan-neck fine adjustment. The movement represents an early in-house development by IWC following its post-war revival. Notable wristwatch references using this caliber include the IWC Calatrava designs of the 1940s and 1950s.