As the El Primero renaissance continued in the 1990's, Zenith made the first major complication addition with the introduction of the flyback-equipped Cal. 405.
Because of the unconventional 4 30 date window placement in the classic El Primero movement, Zenith created a new calibre, Cal. 405B, which moved the date to the 6 00 position.
D 30.0 mm, H 6.5 mm
Power reserve 50 hours