ISA Swiss 2330

Historical ISA quartz calibre with central hours, minutes and seconds and a date display. The 2330/103 sheet specifies 23.30 mm diameter and 2.95 mm height, with quick date correction and a stop device. Swiss-made and Far East assembly examples are documented; a separate later 2330F designation and big-date options require version-specific confirmation. Attribution is to the historical ISA quartz range, not a claim of manufacture by the current ISA Timepieces Swiss SA mechanical-movement company.