Zenith 400 El Primero
Produced by Zenith since 1969
automatic integrated construction, 36,000 bph, 30 mm diameter, 5.7 mm height, 25 rubies, 55 h power-reserve, column wheel design
Examples of watches that use this movement: all Zenith chronographs, Parmigiani, pre-2000 versions of the Rolex Daytona (heavily modified), Daniel Roth