ISA Swiss 9232

Historical ISA quartz movement family with central running seconds and date. Published references identify 9232/1920, /1930, /1940 and /1950 variants sharing 23.30 mm diameter and 4.13 mm thickness. Month, day and 24-hour second-time-zone indications depend on the four-digit suffix and are not universal family functions. Attribution is to the historical ISA quartz range, not a claim of manufacture by the current ISA Timepieces Swiss SA mechanical-movement company.