Zenith El Primero Centenary - 18-carat yellow gold watch

Rare and precious example from Zenith’s “125th Anniversary” commemorative collection, produced in only 500 numbered pieces to celebrate the 125th anniversary of the Le Locle manufacture. This watch bears serial number 414/500, with the corresponding personalized letter branded by the maison and the official limited-series register.

The caliber: at the heart of this timepiece is the legendary El Primero caliber 3021 (ref. 8530 on the certificate), the world’s first high-frequency automatic chronograph movement produced (36,000 vibrations/hour), entirely made and hand-decorated by the Zenith manufacture. Certified as a chronometer by the Official Swiss Chronometer Testing Institute (COSC), with certificate number 4012407. The balance with self-compensating hairspring and the monolithic escapement confirm the technical excellence of this historic caliber.

The case and dial: solid 18-carat yellow gold case, approximately 38 mm in diameter, with crown and pushers at 2 and 4 o’clock. The silvered dial with cool tones features three white subdials — hours (3 hours), minutes (30 minutes), and seconds — with applied gilt arrow markers. The bezel features a tachymeter scale (up to 500 units), with peripheral markers for speed reading. Date window at 3 o’clock. Engraved caseback with reference to the limited series.

Strap: the watch is fitted with a blue lizard skin Rios 1931 strap, Avenue model. Length: 24 cm. Original Zenith 18K gold buckle.

Complete set: this example is accompanied by its original Zenith box in red imitation leather with logo and the year 1865 stamped in gold, the personalized letter dated April 15, 1991 addressed to the first purchaser with red wax seal, the 125th Collection register with the first pieces of the series (nos. 101–105/500 visible), the COSC chronometer certificate, and the original multilingual 125th Collection brochure.

Condition: case with natural patina due to light use, consistent with the age and character of the piece. The dial is in excellent condition. The caliber is functional. Complete movement service recently carried out.

Ideal for a collector seeking a documented, numbered, and complete piece, with verifiable provenance.

• Movement: El Primero Cal. 3021 (8530), automatic, COSC chronometer
• Case material: 18-carat yellow gold
• Diameter: approximately 38 mm
• Functions: hours, minutes, seconds, date, chronograph
• Year: 1991
• Edition: limited 414/500
• Set: box, personalized letter, series register, COSC certificate, original brochure