Unitas 173

The Unitas 173 is a vintage Swiss manual-wind movement from the 17x series, produced in the 1940s. At 13 lignes, it is virtually identical to the Unitas 174, with Unitas assigning different caliber numbers to visually similar movements during this era. This was a common practice in Swiss watchmaking where minor variations in bridge shapes or component specifications warranted different reference numbers. The 173 was produced during Unitas's time under ARSA (Auguste Reymond SA) ownership before becoming part of Ebauches SA. Found in various vintage Swiss watches from the post-war period.