Zenith and Phillips called on the expertise of the independent watchmaker Kari Voutilainen (who has experience in working on and casing vintage chronometer movements) for
link assistance in the restoration and decoration of the original 1950s movements, sourced from Zenith's own archive. Zenith provided their rare caliber 135-O (for Observatory) variant, which
link are the actual movements that competed in the trials at the observatories in Neuchâtel in
link the early 1950s.