Rolex Daytona Steel 16520 Porcelain Mk1 Dial Box and PapersThe first and the greatest of the steel Zeniths Today we are excited to be offering an example of arguably the most desirable 16520 the Porcelain Floating Mk1. The watches are known as Zenith Daytonas due to the fact that the watches had a modified Zenith movement. This example features the glossy lacquered white dial with five lines of text, with the COSMOGRAPH line floating from the rest of the text. A Floating R Serial steel 16520 is a special