This timepiece is not only aesthetically pleasing and of historical importance but also scarce. It boasts a Unitas 431 movement, remanufactured to the exacting standards of Unitas using solely Unitas components. The watch is a substantial 18.5 ligne (41mm) open face (Lépine) pocket watch, crafted entirely in Switzerland during the 1960s, though the inception of the 431 Caliber dates back to the 1940s. This specific model is a featured Arnex watch promoted in their 1972-73 catalog.

Cortebert employed an identical main plate in its 726/736 caliber railroad watch, which was designated for use by the Italian and Turkish railway services. In Italy, the watch was marketed under the Perseo brand, whereas in Turkey, it retained the Cortebert name. Hamilton integrated the Cortebert 669 and 670 movements into their Traffic Special models up until 1969.

Collectors have long speculated whether Ebauches SA facilitated a collaboration between two of its subsidiaries, Unitas, founded by Auguste Reymond, and Cortebert, established by Abraham-Louis Juilliard, through Rolex in the development of the Panerai Radiomir 3646, used by the Italian Navy.