The El Primero caliber was part of the race to develop the first automatic chronograph caliber, and was the first to be introduced in January 1969. It is a true legend, still in production after 50 years, beating at 36. 000 aph (high beat), saved from destruction ordered by the company thanks to the disobedience of Charles Vermont who hid in the attic all the tools and machinery for its production, chosen by Rolex for its Daytona and assembled for 12 years until it could develop a caliber to replace it in 1999-2000 … After ZENITH came back to life in the mid-80s, and after the agreement with Rolex to supply its caliber to the Daytona, ZENITH developed this “De Luca”. Just a heads up: you won’t see the name on the dial or any official documentation; the name it’s known by comes from ZENITH’s importing agent in Italy, De Luca, who was part of the creation of this watch. This is the Mark III version, which includes mineral crystal and an inverted panda dial (black dial with silver subdials), date at 4 o’clock, Mercedes hands and diving bezel. The set includes its original vintage case, and the look is completed with the beautiful state of tritium on dial and hands, and with a 22 mm brown strap that looks spectacular. Truly a watch that is an important part of watchmaking history, still with a very interesting price. If you want to know more about the history of ZENITH and the De Luca, we recommend this link.