Milano Straps
← ZenithSearchCart
Menu

Zenith · Defy

Strap for Defy El Primero 21 Titanium / Diamond / Skeleton / Alligator

Takes 23 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width

23mm
23 mm strapsAll Zenith
Lug width23 mm
Case diameter44 mm
Reference33.9000.9004/78.R582
FamilyDefy
MovementZenith caliber El Primero 9004 Hours, Minutes, Small Seconds | Chronograph | Chronometer, Power Reserve Indicator
CaseTitanium

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

View →

The Defy 33.9000.9004/78.R582, seen from the bench

The Zenith Defy El Primero 21 Titanium 33.9000.9004/78.R582 is a 44 mm chronograph launched in 2017, featuring a skeletonized titanium case that exposes the legendary El Primero 9004 movement through a display caseback and 12 o'clock window. The El Primero 9004 caliber maintains the iconic 36,000 beats per day (10 Hz) frequency, with integrated power reserve indicator, chronograph hour and minute counters, and central small seconds. The 23 mm lug width is integrated into the case structure, requiring a dedicated strap for proper proportions and visual harmony.

Frequently asked questions

What is the exact lug width of the Zenith Defy 33.9000.9004/78.R582?

The lug width of the Zenith Defy 33.9000.9004/78.R582 is 23 millimetres. This non-standard measurement is integrated into the structural design of the case and requires dedicated straps to ensure harmonious fit and mechanical stability of the lugs.

Which strap material is most suitable for the Zenith Defy 33.9000.9004/78.R582?

Alligator leather dyed in deep blue or dark brown is the most balanced choice: the natural grain dialogue with the modern titanium geometry, developing characteristic patina over time. Vegetable-tanned calf leather offers daily versatility and controlled natural ageing. Shell Cordovan is reserved for those who understand the potential of ultra-high-density leather.

How do you change the strap on the Zenith Defy 33.9000.9004/78.R582?

The Defy uses a standard straight lug attachment system (23mm spring bar) accessible from the back of the case. Remove the caseback following original instructions, proceed with spring bar replacement using dedicated tools without exerting pressure on the case, and reinstall the caseback ensuring proper sealing. For critical operations, entrust an authorised service centre.

Is it possible to use a quality aftermarket strap on this Zenith?

Yes, provided the strap respects exactly the 23mm lug width and is manufactured to construction standards comparable to the original. European artisanal straps in full-grain leather, with solid deployante closures and natural silk stitching, guarantee mechanical compatibility and superior aesthetic longevity.

What is the average lifespan of a leather strap on a Zenith Defy 33.9000.9004/78.R582 in daily use?

A high-quality leather strap (alligator, cordovan, vegetable-tanned calf) withstands 4-7 years of daily use, provided regular maintenance (avoid prolonged baths, dry after intense perspiration, condition with specific creams every 12 months). Structural ageing varies depending on climate, frequency of use and care routine.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

Request an appointment →

Casati Milano · Via XX Settembre 15, Milan · by appointment only