Now for the twist. link This link reference 16520 Daytona does not rely on a Zenith movement. In the final two years of production, Rolex started to produce transitional Daytonas that featured Rolex's in-house caliber 4030, which, along with its generational upgrade, the 4130, would go on to power all Daytonas after 1999. This is one of those odd overlaps that allow you to enjoy a special recipe, the neo-vintage case and look of a model introduced in 1988 with a link thoroughly modern Rolex inside.