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Black Tag Watches
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Aventura FL 33180 USA
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Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
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The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
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Pre-Owned Zenith El Primero Chronomaster Triple Calendar Moon Phase Chronograph Steel — Silver Dial, Full Set, Recently Serviced (Ref. 01.0240.410)
In 1969, three Swiss watchmaking groups raced to produce the first automatic chronograph. Zenith’s answer was the only one that beat at 5 Hz — and half a century later, it is the only one still in continuous production.
Available now at Black Tag Watches (Aventura, Florida), this pre-owned example — reference 01.0240.410 — is cased in 40mm stainless steel with a silver dial, powered by the manufacture calibre El Primero 410 at 5 Hz, and offered in mint condition with a full set and a Zenith service receipt dated June 2026, under service warranty until June 2027.
What Is the Zenith El Primero Chronomaster Triple Calendar Moon Phase?
One of the Most Important Automatic Chronograph Calibres in Modern Watchmaking
The pre-owned Zenith El Primero Chronomaster Triple Calendar Moon Phase is the stainless-steel calendar-and-moonphase execution of one of the most historically important automatic chronograph calibres in modern Swiss watchmaking. The El Primero — the name is Esperanto for “the first” — was launched by Zenith in January 1969, alongside the Seiko 6139 and the Chronomatic consortium’s Calibre 11 (a joint development by Heuer, Breitling, Hamilton, and Buren). Experts still argue about which was truly first. What is not disputed is that the El Primero was the only one of the three to beat at 36,000 vibrations per hour (5 Hz), delivering chronograph timing accurate to one-tenth of a second, and the only one to combine automatic winding with a fully integrated column-wheel chronograph rather than a modular architecture mounted onto a time-only base. It is also the only one of the three still in continuous production today.
The Triple-Calendar Configuration
The reference 01.0240.410 is one of the more complex executions in the modern El Primero family — a full triple calendar plus moon phase layered onto the 5 Hz chronograph base. Production of the 410 calibre ran only from 1994 through 1998, making the triple-calendar-and-moon-phase configuration one of the shorter-lived and more specifically-instrumented Chronomaster variants. For collectors of pre-owned Zenith chronographs, this is the reference where the calibre’s mechanical substance is matched by a genuinely complex dial.
Dial & Case Design: Steel Chronomaster, Silver Complex Dial
Case Proportions and Chronomaster Vocabulary
The 40mm stainless steel case stands 13mm thick, with brushed and polished flanks framing a three-part construction typical of the Chronomaster line. The calendar-and-moonphase execution sits within the maison’s mid-1990s dress-chronograph vocabulary, where the case was sized for wearability rather than for statement. At 40mm, the reference wears as a genuine daily dress chronograph — a proportion that has aged considerably better than the oversized cases that followed in the 2000s.
The Silver Triple-Calendar Dial
The silver dial is arranged with unusual complexity for an El Primero — a full triple calendar plus moon phase across four apertures and three sub-dials. Reading clockwise: a month aperture at 2 o’clock, a 30-minute counter at 3, a date aperture between 4 and 5, a 12-hour counter integrated with the moon phase indicator at 6 o’clock (the moon disc reads through two apertures within the register), a small-seconds sub-dial at 9, and a weekday aperture at 10. Roman numeral hour markers ring the periphery over a tachymetre scale, and slim polished hands read cleanly against the silver field. “Chronomètre” is printed on the dial — the reference is COSC-certified, with the accompanying certificate included in the original delivery. The dial reads as maximally-utilised without feeling cluttered — the specific compositional discipline the Chronomaster line has always used to distinguish itself.
Movement: Manufacture Zenith Calibre El Primero 410 — 5 Hz
The Base 400 and the Calendar Module
Inside is the manufacture Zenith calibre El Primero 410 — a Swiss automatic chronograph movement of 31 jewels comprising 390 parts, beating at 36,000 vph (5 Hz) with an approximate 50-hour power reserve, COSC-certified for chronometry. The 410 is the calendar-and-moonphase execution of the base calibre 400 — the El Primero platform itself — with an additional module carrying the triple-calendar and moon-phase complications mounted above the base. The 5 Hz beat rate remains unusual even today: it delivers chronograph timing to one-tenth of a second, a resolution most automatic chronographs at any price cannot match.
The Rolex Daytona Connection
The base 400 is the same calibre architecture Rolex used inside every automatic Daytona reference 16520 produced from 1988 through 2000, where it appeared as the reworked Rolex calibre 4030. Rolex chose the El Primero over any other automatic chronograph available at the time for a specific reason: no other automatic chronograph running in the late 1980s beat at 5 Hz, and no other combined that frequency with a fully integrated column-wheel architecture. That Rolex used the El Primero as the basis for the modern Daytona is one of the most consequential cross-brand horological facts of the past half-century — and it is the specific historical argument that separates the El Primero 400 family from every other mid-tier automatic chronograph calibre available today.
Movement Specifications
Specification
Detail
Calibre
Zenith El Primero 410, automatic chronograph
Base
El Primero 400 + triple-calendar/moon-phase module
Components
390 parts, 31 jewels
Frequency
36,000 vph (5 Hz)
Power reserve
~50 hours
Chronograph
Integrated column-wheel
Certification
COSC chronometer
Caseback
Sapphire display
Condition, Provenance & Service History
Full Set with Documented June 2026 Service
Condition is mint. Provenance is complete: the watch is offered with its original Zenith presentation box, five-language instruction booklet, COSC chronometer certificate, hangtag, and an empty original warranty card. Crucially, this example also carries a Zenith service receipt dated June 2026 and remains under Zenith’s service warranty through June 2027 — a documented recent factory service that materially affects long-term ownership on a movement of the calibre 410’s complexity, where authorised Zenith service is the principal determinant of long-term cost of ownership. For a mid-1990s Chronomaster now more than two decades old, a recent authorised service with an active warranty period is the signal that separates this example from a comparable listing without documented service history.
Condition and Accessories
Detail
Information
Condition
Mint
Box
Original Zenith presentation box
Papers
Stainless steel tang
Service
Zenith receipt June 2026, warranty to June 2027
Strap
Black alligator, pre-owned mint
Buckle
Stainless steel tang
Full Specifications — Zenith El Primero Chronomaster Triple Calendar Moon Phase 01.0240.410
Specification
Detail
Brand
Zenith
Collection
El Primero Chronomaster Triple Calendar Moon Phase
Reference
01.0240.410
Production
Production
Case
Stainless steel, 40mm
Thickness
13mm
Dial
Silver, triple calendar + moon phase
Layout
Month 2, 30-min 3, date 4–5, 12-hr + moon 6, small sec 9, weekday 10
Markers
Roman numerals
Bezel
Tachymetre scale
Movement
Zenith El Primero 410, automatic chronograph
Base
El Primero 400 + calendar module
Components
390 parts, 31 jewels
Frequency
36,000 vph (5 Hz)
Power reserve
~50 hours
Chronograph
Integrated column-wheel
Certification
COSC chronometer
Caseback
Sapphire display
Strap
Black alligator, pre-owned mint
Buckle
Stainless steel tang
Condition
Mint
Box & Papers
Full set
Service
Zenith June 2026, warranty to June 2027
Why Buy a Pre-Owned Zenith El Primero Chronomaster Triple Calendar?
A Movement Punching Above Its Price Band
The 01.0240.410 has always occupied a specific corner of the pre-owned chronograph secondary market — recognised by collectors who read calibre lineage as a substantive quality signal, and largely bypassed by buyers whose category discipline stops at the more common El Primero time-and-chronograph references. The 410 calibre production ran only from 1994 through 1998, and the triple-calendar-and-moon-phase configuration is one of the more complex executions in the modern El Primero family. Full-set examples from within the original production window with documented recent factory service are increasingly hard to source, and the 01.0240.410 offers a level of horological substance that its price band does not fully reflect.
The Daytona Calibre Family, Serviced and Documented
Against contemporary Swiss chronographs at retail in the same price band, this Zenith offers a fully-integrated column-wheel 5 Hz chronograph calibre from the same manufacture family that Rolex used inside the modern Daytona for twelve years, with a triple-calendar-and-moon-phase module, COSC certification, and a documented factory service within the past six months. It is the class of reference where the movement punches meaningfully above its price band — and the recent service, with warranty through June 2027, removes the single largest ownership variable on a complicated vintage chronograph.
Available at Black Tag Watches — Aventura, Florida
Black Tag Watches is a pre-owned luxury watch dealer based in Aventura, FL, specialising in rare, certified, and fully documented timepieces from Zenith and the world’s leading Swiss manufactures.
View the Zenith El Primero Chronomaster Triple Calendar Moon Phase — Full Details & Pricing
A mid-1990s Chronomaster with a 5 Hz El Primero, triple calendar, moon phase, and a service receipt from June 2026 — the quiet argument for owning a Zenith rather than the more obvious chronograph names.
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