Zenith · Class

Strap for Class Sport El Primero Stainless Steel / Black / Strap

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width

20mm

20 mm straps All Zenith

Lug width20 mm

Case diameter40 mm

Reference03.0510.400/24.C492

FamilyClass

MovementZenith caliber El Primero 400 Hours, Minutes, Small Seconds | Date | Chronograph, Column wheel

CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

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

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Straps for the Class 03.0510.400/24.C492

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Class 03.0510.400/24.C492, seen from the bench

The Zenith Class 03.0510.400/24.C492 is a stainless steel chronograph featuring the celebrated El Primero 400 caliber, beating at 5Hz with 1/10-second resolution. The 40mm steel case measures 13.7mm thick and pairs with a 20mm lug width, a classic proportion from the 1970s–1990s sports watch era. Water-resistant to 100 meters, this timepiece embodies the structural elegance and mechanical complexity of European sport chronographs.

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.

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