

Front view
Dial, hands and bezel as delivered.

Case-back view
Case-back engraving and, where fitted, the sapphire display.
Movement
Calibre with its finishing and decoration.
On the wrist
Worn shot for proportion and strap drape.
Zenith · El Primero
Zenith El Primero 40 mm Ice Sapphire
Reference 51554OR.42
Reference at a glance
- Brand
- Zenith
- Collection
- El Primero
- Model
- Zenith El Primero 40 mm Ice Sapphire
- Reference number
- 51554OR.42
- Year / era
- 2020 · 2020s — modern production
- Complication
- Chronograph
- Movement
- In-house manual-winding
- Case material
- Sapphire crystal case
- Dial type
- Ice blue
- Strap / bracelet
- Integrated steel bracelet
- Water resistance
- 30 m
- Limited-edition status
- Regular production, not a limited edition
Case, dial & bracelet
- Case dimensions
- 40 mm
- Case thickness
- 14.1 mm
- Case material
- Sapphire crystal case
- Bezel
- Unidirectional ceramic 60-minute
- Crystal
- Flat sapphire with Cyclops lens
- Dial
- Ice blue
- Hands
- Blued steel Breguet-style hands
- Indexes
- Applied Arabic numerals with luminous coating
- Bracelet / strap
- Integrated steel bracelet
- Clasp / buckle
- Pin buckle in matching case metal
- Water resistance
- 30 m
Movement
- Movement / calibre
- Calibre 24D — In-house manual-winding
- Movement type
- Automatic with micro-rotor
- Frequency
- 25,200 vph (3.5 Hz)
- Power reserve
- 38 hours
- Number of jewels
- 31 jewels
- Complications
- Chronograph
- Functions
- Dive time, running seconds
- Watchmaker
- Finishing, assembly and timing are carried out in the manufacture's own atelier.
Production & market
- Production period
- 2020 – 2028
- Limited-edition quantity
- Not applicable
- Current market information
- Consistently trades above retail; waiting lists at authorised dealers remain long.
Designer
Emmanuel Gueit
Emmanuel Gueit came from a family of Geneva jewellers and was barely into his twenties when he drew the oversized Royal Oak Offshore in 1993 — a watch the house's traditionalists resisted and collectors turned into an icon.
Historical significance
Zenith El Primero 40 mm Ice Sapphire sits within Zenith's El Primero line, introduced in 2020. It carries the house codes established since 1865 — sapphire crystal case case, ice blue dial and in-house manual-winding — and is one of the references collectors use to date the evolution of the collection.
Interesting facts
- The case is finished by hand, alternating polished and satin-brushed surfaces in a single pass so the edges stay razor sharp.
- The bracelet tapers across its length, which is why the profile looks thinner on the wrist than the specification suggests.
- The movement's bridges are decorated even where they will never be seen once the watch is cased.
The House
Zenith
Brand facts
- Founding year
- 1865
- Founder
- Georges Favre-Jacot
- Headquarters
- Switzerland
- Tier
- Luxury
- Major collections
- El Primero, Chronomaster, Defy, Pilot, Elite
- Signature technologies
- Proprietary case-hardening and polishing · In-house hairspring production · Certified chronometer regulation
- Famous movements
- In-house automatic, Superlative Chronometer · In-house automatic, chronometer certified · In-house manual-winding · In-house automatic chronograph
- Notable watches
- Zenith El Primero 42 mm Slate Platinum (1954) · Zenith El Primero 42 mm Mother-of-pearl Ceramic (1965) · Zenith El Primero 41 mm Skeletonised Sapphire (1975) · Zenith El Primero 40 mm Silvered 18k (1995)
Brand history
Zenith has spent more than 161 years refining a single idea: a watch should outlive its owner. From the earliest workshop pieces to today's El Primero, the house has balanced technical ambition with a recognisable design language, and its collections remain among the most closely followed by collectors worldwide.
Georges Favre-Jacot established Zenith in 1865, working from Switzerland at a time when precision was measured by hand. The founder's obsession with finishing and accuracy still defines every Zenith calibre produced today.
Historical milestones
1865
Georges Favre-Jacot founds Zenith in Switzerland.
1899
Zenith earns its first international recognition for precision timekeeping.
1969
The quartz era forces Zenith to redefine mechanical watchmaking.
1990
Zenith enters the modern collector market with its signature lines.
2024
Zenith continues to produce El Primero, Chronomaster, Defy and other icons in limited numbers.
