The Zenith El Primero is undoubtedly a legendary automatic chronograph movement introduced in 1969. It is renowned as one of the first automatic chronograph movements ever created, marking a significant milestone in the history of watchmaking. Not only was it designed to be highly accurate and precise, but it also represented a breakthrough in horology with its high frequency of 36,000 VPH. The El Primero caliber 3019PHC, in particular, is highly regarded for its exceptional quality and performance. Interestingly, the El Primero movement even served as the base caliber for Rolex's first self-winding chronograph, which was used in the iconic Daytona reference 16520 introduced in 1988.
Amongst the vintage era, the round-shaped El Primero A386 is the most recognized reference. However, its sister reference, the A3817, is considered even rarer than the A386, with an estimated production of only 1,000 pieces. The case of the A3817 showcases angular and sculpted design elements that were popular during its production period, while the dial features a combination of colors, with subsidiary dials in blue, light grey, and anthracite. The subdial at 9 o'clock stands out with a unique blue hand and blue indexes, creating a subtle contrast against the light grey register. This vibrant dial design represented a departure from the more subdued aesthetics of the 40s and 50s, offering a modern and colorful look for sports watches.
The present example is exceptionally well-preserved, which is remarkable considering its age of over 50 years. The engraving "SP 1301" on the inner caseback refers to the casemaker Spillman, denoted by "SP". It is also accompanied by its original "ZKM" endlinks and features the highly desirable original-styled Gay Frères ladder bracelet, stamped for the fourth quarter of 1971. With its exceptional condition and originality, this watch possesses all the qualities sought after by collectors, making it a highly collectible vintage Zenith timepiece.