Zenith El Primero A3817

This Zenith El Primero A3817 from the 1970s is a classic automatic chronograph with strong character. The striking tri-color dial is housed in a cushion-shaped stainless steel case and is offered here together with its original Gay Frères ladder bracelet — a combination that is both rare and highly sought-after today.

The watch is powered by the legendary El Primero caliber, introduced by Zenith in 1969. This high-frequency movement operates at 36,000 vibrations per hour, delivering exceptional rate stability, and also features a quick-set date function — an outstanding and uncommon feature for the 1970s.

Visually, reference A3817 is inspired by the famous A386, yet it differs in several key details. Most distinctive is the running seconds sub-dial at 9 o’clock, featuring blue markers and a blue hand. Signature El Primero elements such as the red paddle-tip chronograph seconds hand, the date window between 4 and 5 o’clock, and the grey outer ring with tachymeter and pulsation scales complete the well-balanced and dynamic dial design.

The cushion-shaped case measures approximately 38 mm in diameter and, thanks to its relatively slim profile, wears elegantly and very comfortably on the wrist. The watch is complemented by its original, lightweight Gay Frères ladder bracelet, which not only enhances the overall aesthetics but also offers excellent wearing comfort.

With an estimated production of only around 1000 pieces, the A3817 is even rarer than the A386. Overall, this is an attractive and authentic vintage chronograph that convincingly combines design, technology and history — an impressive wristwatch with strong character.

Condition Report
Dial: very good condition – light, natural patina – original tritium lume in hands and markers – matching patina across hands and hour markers – applied Zenith star logo – signed "Zenith Chronograph Automatic El Primero" and "swiss made T".

Case: Very good condition – very lightly refinished – intact brushing – crisp serial number engraving on the caseback – correct crown with NATO logo – correct caseback engravings: "SP 1301" (Spillman case).

Movement: Automatic Zenith El Primero caliber 3019 PHC with quick-set date – timegrapher results: rate deviation +5s/day, beat error 0.2 ms, amplitude 275 degrees – chronograph starts, stops, and resets correctly.

Bracelet: original Gay Frères stainless steel bracelet (ladder bracelet) – slight stretch – hardly any signs of wear – Zenith folding clasp – bracelet length: 18–25 cm.

Serial number: 232Exxx

Int.Exe.: 54246