Zenith
Zenith Chronomaster Sport Two-Tone 51.3100.3600/21.R951
The Zenith Chronomaster Sport Two-Tone (reference 51.3100.3600/21.R951) is a 41 mm Two-tone steel/18k rose gold watch with a black dial. It runs on the automatic caliber El Primero 3600 with a 60-hour power reserve and is water resistant to 100 m.
Specifications
Case
- Reference
- 51.3100.3600/21.R951
- Collection
- Chronomaster Sport
- Case size
- 41 mm
- Thickness
- 13.6 mm
- Case material
- Two-tone steel/18k rose gold
- Case shape
- Round
- Crystal
- Sapphire
- Water resistance
- 100 m
- Bracelet / strap
- Rubber strap
Dial and bezel
- Dial
- Black
- Bezel
- Rose gold bezel with 1/10th-second scale
Movement
- Movement
- Automatic
- Caliber
- El Primero 3600
- Power reserve
- 60 hours
- Frequency
- 36,000 vph
- Jewels
- 35
- Functions
- Small seconds, Date, Chronograph (1/10th second)
Production
- Production
- Current
How it compares within the Chronomaster Sport family
Side by side with other references in the same collection, from the catalog.
| Reference | Size | Material | Dial | Caliber | Years |
|---|---|---|---|---|---|
| 51.3100.3600/21.R951 (This watch) | 41 mm | Two-tone steel/18k rose gold | Black | El Primero 3600 | — |
| 03.3100.3600/21.C822 | 41 mm | Stainless steel | Black | El Primero 3600 | 2021– |
| 03.3100.3600/21.M3100 | 41 mm | Stainless steel | Black | El Primero 3600 | 2021– |
| 03.3100.3600/69.M3100 | 41 mm | Stainless steel | White | El Primero 3600 | 2021– |
| 18.3100.3600/69.C920 | 41 mm | 18k rose gold | White | El Primero 3600 | 2023– |
| 18.3101.3600/21.M3100 | 41 mm | 18k rose gold | Black | El Primero 3600 | — |
| 51.3100.3600/69.M3100 | 41 mm | Two-tone steel/18k rose gold | Silver / White | El Primero 3600 | 2023– |
| 95.3100.3600/39.M3100 | 41 mm | Titanium | Grey | El Primero 3600 | 2024– |
| 95.3100.3600/39.R951 | 41 mm | Titanium | Grey | El Primero 3600 | 2024– |
About the Chronomaster Sport family
The Chronomaster Sport was introduced in 2021 as a 41 mm sports chronograph with a ceramic bezel graduated to a tenth of a second, matching the El Primero 3600 inside.
The catalog lists more than fifty references in steel, rose gold and steel and rose gold, with black or white dials and the tri-colour counters of the El Primero tradition, plus titanium and special editions. Dealers identify the metal and dial from the reference, check the bracelet and the condition of the ceramic bezel, and ask for the box and papers.
Quick answers
- What size is the Zenith Chronomaster Sport Two-Tone 51.3100.3600/21.R951?
- The Zenith Chronomaster Sport Two-Tone 51.3100.3600/21.R951 has a 41 mm case, 13.6 mm thick.
- What movement does the Zenith Chronomaster Sport Two-Tone 51.3100.3600/21.R951 use?
- It uses the automatic caliber El Primero 3600, with a 60-hour power reserve.
- How water resistant is the Zenith Chronomaster Sport Two-Tone 51.3100.3600/21.R951?
- It is water resistant to 100 metres.
- Is the Zenith Chronomaster Sport Two-Tone 51.3100.3600/21.R951 still in production?
- Yes, it is a current reference.
- What is the Zenith Chronomaster Sport Two-Tone 51.3100.3600/21.R951 made of?
- The case is Two-tone steel/18k rose gold. Bracelet or strap: Rubber strap.
Catalog facts checked September 2026.