You may know that Rolex used Zenith’s El Primero chronograph movement in the Daytona for a few years - but did you know that they modified it so heavily, that only 50% of the components found in the Daytona’s 4030 caliber were original to the El Primero?
Just one of themanythings you will learn in this excellent, three part series on Rolex’s chronograph, the Cosmograph Daytona, written by noted collector and expert, Mr. Paul Boutros.
- Source: hodinkee.com