Zenith
El Primero 49.2520.400/98.R578— lug 22mm

The lug width of the Zenith El Primero 49.2520.400/98.R578 is 22mm. This measurement is determined by the geometry of the 45mm ceramic case and its original attachment lugs. To verify accurately, position a digital calliper perpendicularly between the two attachment points, measuring from the inner centre of one lug to the inner centre of the other.

For this technical chronograph, straps in genuine alligator with fine grain are recommended—offering sober elegance and exceptional durability—or vegetable-tanned calf leather that maintains colour legibility over time. For professional applications, FKM rubber or technical cordura provide waterproofing and minimal maintenance. The choice depends on intended use and desired aesthetics.

Strap replacement requires a spring bar removal tool. Position the watch on a cushion with the strap facing upward, locate the two access holes to the lugs, insert the tool to compress the spring bar and extract it downward. Repeat on the opposite side. Installation of the new strap follows the reverse procedure. Extreme care is recommended to avoid damaging the ceramic case.

Yes. Milanostraps offers a dedicated collection of 22mm-compatible straps, available in numerous materials and colours, customisable in dimensions, initials and stitching thread. All straps are specifically dimensioned for this lug width and ready for fast dispatch. For highly specialised requirements, the Casati Milano atelier creates bespoke straps with personal leather selection.

Longevity depends on leather quality and use. A strap in high-quality alligator or vegetable-tanned calf has an average lifespan of 3-5 years under normal wear, extendable with regular maintenance and rotation with other straps. Constant exposure to moisture, perfumes and detergents reduces lifespan. FKM rubber straps endure longer, up to 7-10 years, maintaining superior structural integrity.