The Watch: The 16523 is the two-tone Zenith Daytona, produced from 1988 through 2000. When Rolex transitioned the Daytona from manual wind to automatic, they didn't develop their own chronograph movement. Instead they went to Zenith and took the El Primero, one of the first automatic chronograph movements ever produced, then modified it with roughly 200 changes. Rolex re-engineered the beat rate down from 36,000 vph to 28,800, swapped in their own escapement components, and added a Breguet overcoil to the balance spring. The result was the caliber 4030, which powered the Daytona for twelve years until the fully in-house 4130 replaced it.
The case is 40mm in Rolesor with an 18k yellow gold tachymeter bezel, screw-down pushers, and a Triplock crown. This is an A-serial example from circa 1999, making it a later production Zenith Daytona.
Condition: Very good condition. Bracelet will fit a wrist up to 6.75"
