The Rolex Daytona Ref.16520 was the last model in Rolex's collection to contain the Zenith movement, even though the Zenith movement had been a great success. Rolex didn't like the fact that was not 100% manufactured by them alone. The housing calibre 4130, containing the new Rolex movement was launched during the baselworld exhibition.
Other versions releases of this model Ref. 16520 include:
2000- stainless steel and gold, yellow gold, and white gold.
2004- white gold with black or white dials.
2008- everose gold