Accompanied by République et Canton de Neuchâtel Observatoire Astronomique et Chronométrique Duplicata of the Bulletin de Marche dated 5 April 1967.
The famous caliber 30 mm. was designed by Henri Kneuss, launched in 1939 and would mark the history of watchmaking for a quarter of a century.
It beat numerous records at the Neuchâtel, Geneva and Kew Observatory Contests and was considered the most precise wristwatch caliber ever tested. Calibre 30 continued to make its mark until 1967, the last year of the competitions.