Cyma Clamshell Tank Art Deco

An aspect of 20th-century watchmaking that we love is how technical innovations affected the aesthetics of a watch. Take for instance this amazing Cyma; it is an early example of a waterproof case aka a Clamshell case. The case is held in place by 4 screws in the back which seal the movement and dial from atmospheric conditions.

This timepiece is a combination of two remarkable features: it is an exceedingly rare oversized rectangular watch for its era, and it stands out as an anomaly in terms of its  condition, having retained its pristine state for over 80 years with a beautiful dial patina.