Strap for Mirage 38 Sienna

The Berneron Mirage M38S features a 20mm lug width, a deliberate design specification that ensures harmonious proportions with the 34mm case diameter. This width is critical to the aesthetic balance of the case and cannot be adjusted; any strap must conform to this measurement for proper installation without the use of reducers.

For a yellow gold M38S, we recommend alligator leather with a satin patina as the primary choice, as it emphasises the sophistication of the precious metal case. Alternatively, vegetable-tanned calf leather offers versatility and elegant ageing. For sport contexts, a 2-ply fabric NATO provides restrained minimalism; quality rubber represents the contemporary option. In all cases, favour warm tones (cognac, brown) or deliberate contrast (black).

The strap is secured via spring bars (lugs) that pass through the case lugs. Using a specialised spring bar tool, apply gentle pressure to extract the pin and release the old strap. Position the new strap (with 20mm lug width), aligning the holes to the lugs, and reinsert the pin until it locks into place. For precious metal cases, we recommend having this performed by a qualified watchmaker.

Yes, provided they strictly conform to the 20mm lug width specification. Any artisanal strap of quality (leather, alligator, shell cordovan, rubber) matching this width can be installed without case modification. We advise against generic mass-market straps: the Mirage deserves partners of comparable material integrity.

Longevity depends on material, tanning method and wear patterns. A vegetable-tanned leather strap of quality (alligator, calf, shell cordovan) on a dress watch worn 2–3 times weekly provides 4–6 years of life before replacement is needed. The leather will develop a beautiful patina, but will gradually lose elasticity at the lugs. A NATO or rubber strap offers superior longevity (7–10 years) but less aesthetic evolution.