Strap for Pilot's Watch Chronograph Stainless Steel / Black / French / Strap

The lug width of the reference IW3706-04 is exactly 20 millimetres. This measurement represents the distance between the lugs – the pins anchored to the watch case where the strap attaches. Verifying this specification before purchasing an aftermarket strap is essential to avoid irreversible visual asymmetries.

For the IW3706-04, we recommend dark alligator straps for formal environments, as the natural texture and fine grain complement the black dial and applied indices. For informal settings, vegetable-tanned calf leather offers authentic patination. For pilots and technical environments, a NATO strap in woven nylon remains the most historically coherent choice.

Strap replacement requires a spring bar tool to disengage the elastic pins anchoring the strap to the case lugs. Position the tool underneath the lug, apply gentle upward pressure, and slide the worn strap free. Ensure the spring bars remain seated in their original position before attaching the new strap.

Yes, any strap with a 20-millimetre lug width is compatible with the IW3706-04. The critical requirement is precise width measurement: a strap measuring 18 or 22 millimetres would create visible gaps at the lugs. We recommend bespoke artisanal straps crafted to specification for assured fit and construction quality.

A premium leather strap (alligator, vegetable-tanned calf) on a daily-wear watch typically lasts 3–5 years, depending on usage, climate, and maintenance. Vegetable-tanned leather develops surface creases after 2–3 years of intensive use – markers of authentic ageing, not functional compromise. A vulcanised rubber strap maintains flexibility for 7–10 years.