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Zenith Defy Extreme Diver 42.5mm Mens Watch Black Interchangeable Strap
Ref. 95.9600.3620/21.I300
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Stepping up in the same dial colour
The angular 42.5mm titanium case sits on a black FKM rubber strap, with a tool-free interchangeable system that also includes a titanium bracelet and a recycled fabric strap. A unidirectional black ceramic bezel and helium escape valve support the 600m water resistance rating, while a flat sapphire crystal with double-sided anti-reflective treatment covers the dial. The caseback is sapphire too. The black dial carries a starry-sky pattern, with hands and indices coated in Super-LumiNova X1. Inside, the El Primero 3620 SC automatic runs at 36,000 vph and delivers a 60-hour power reserve.
- Reference
- 95.9600.3620/21.I300
- Brand
- Zenith
- Collection
- Defy
- Case size
- 42.5mm
- Case material
- Titanium
- Case shape
- Round
- Dial
- Black
- Crystal
- Sapphire
- Bezel
- Unidirectional rotating
- Movement
- Automatic
- Calibre
- El Primero 3620 SC
- Functions
- Small seconds
- Water resistance
- 600m
- Bracelet / strap
- Titanium bracelet
- Strap colour
- Silver
- Lume
- Super-LumiNova
- Retailer
- Mappin & Webb
Additional specifications
- Power reserve
- 60 hours
- Strap
- Interchangeable
Learn more about Zenith
Georges Favre-Jacot founded Zenith in Le Locle in 1865, aged twenty-two, with an idea that was radical for the Swiss industry: bring every trade needed to make a watch — movement, case, dial, hands — under one roof and one management. The integrated manufacture was largely his invention, and the Le Locle site he built is still in use.
The approach produced results at observatory trials, where Zenith accumulated more precision awards than any other manufacture. The name itself came from a calibre Favre-Jacot considered the summit of his work.
Its defining achievement is the El Primero of 1969, developed over seven years and announced in the same year as the Heuer-Breitling consortium's Calibre 11 and Seiko's 6139. It was an integrated automatic chronograph beating at 36,000 vibrations per hour, allowing measurement to a tenth of a second — a frequency almost nothing else matched for decades.
It nearly did not survive. When American owners ordered the mechanical tooling scrapped during the quartz crisis, a watchmaker named Charles Vermot hid the plans, presses, and cams in a walled-off attic. When demand for mechanical chronographs returned, Zenith could restart production because of him. Rolex used the El Primero in the Daytona from 1988 to 2000.
LVMH acquired Zenith in 1999.
- 1865
- Georges Favre-Jacot founds the integrated manufacture at Le Locle.
- 1969
- The El Primero automatic chronograph debuts at 36,000 vph.
- 1975
- Charles Vermot hides the El Primero tooling from destruction.
- 1988
- Rolex adopts the El Primero for the Daytona.
- 1999
- Acquired by LVMH.
Also in 5 collections
This watch appears in the Zenith Defy range (23), Automatic Watches (1,763), Sports Watches (794), Dive Watches (567) and Titanium Watches (179).
What the specifications mean
A mechanical watch built to be worn hard and got wet.
Strengths
- 600m water resistance, rated for actual diving
- Sapphire crystal, which resists scratching
- Luminous hands and markers for low light
- Sits in the lower half of Zenith's range as we list it
Zenith Defy Extreme Diver alternatives
Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.
| Specification | 95.9600.3620/21.I300 | SUPERNOVA-AL-N-B | 1-39-11-06-60-33 |
|---|---|---|---|
| Price | £10,600 | £8,400 | £8,700 |
| Case size | 42.5mm | 40mm | 39.5mm |
| Water resistance | 600m | — | — |
| Movement | Automatic | Automatic | Automatic |
| Strap | Titanium bracelet | Stainless steel bracelet | Rubber strap |
| Power reserve | 60 hours | — | — |
| This watch |
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Your new watch
Frequently asked questions, and things you should know about this watch
Can I swim with it?
Yes. At 600m it is rated for swimming, snorkelling and recreational diving.
Water resistance explainedWill the glass scratch?
Unlikely. Sapphire is second only to diamond in hardness and shrugs off everyday marking.
Sapphire, mineral and acrylic comparedDoes it need a battery?
No. It is automatic — the motion of your wrist winds it, and there is no cell to replace.
Quartz, automatic and solar comparedHow long does it run for when it's not worn?
About 60 hours fully wound — enough to survive a night off the wrist, but not a full weekend.
Is it a men's or women's watch?
Listed as men's.
Cheapest place to buy
Mappin & Webb is the only UK retailer we track stocking this reference, so there is nothing to compare it against today.
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