Strap for Conquest 41 Automatic Ceramic

The lug width of the Longines Conquest L3.657.4.56.0 is 21.00mm. This dimension is model-specific and requires straps manufactured for this exact width, as it does not conform to standard strap widths (18mm, 20mm, 22mm). The lug width is measured using a digital calliper at the strap bars—the points where the strap anchors to the case lugs.

For the Conquest in stainless steel and black ceramic, we recommend three options in order of versatility: 1) Alligator in anthracite grey or dark brown, which creates visual contrast and develops progressive patina over time; 2) Vegetable-tanned calf leather, for those seeking durable elegance and controlled ageing; 3) NATO military-spec in ballistic nylon black, for daily extreme use as an instrument watch. FKM rubber is the absolute choice for aquatic environments or highly abrasive conditions.

The Conquest uses threaded spring bars (drizzaglie) to anchor the strap to the case lugs. Procedure: 1) Position the watch on a soft cushion, dial facing upwards; 2) Using a precision strap tool with 1.5mm tips, gently unscrew the bars from both sides; 3) Remove the old strap; 4) Insert the new 21mm strap and reinsert the bars, tightening with moderate torque (approximately 0.5–0.7 Nm); 5) Do not force—the mechanism is delicate. If inexperienced, consult a specialised atelier.

Yes, absolutely, and it is recommended. Since the 21mm lug width is non-standard, quality artisanal aftermarket straps (such as those from MilanoStraps) are often the only way to vary the watch's appearance without compromise on fit. Ensure the strap is constructed with this specific width and that the spring bars are compatible with the Conquest's lug system. A specialised sartorial atelier like Casati Milano can also customise the strap width if needed.

Durability depends on the tanning method, usage intensity, and climate. An alligator or vegetable-tanned calf strap, worn daily, typically lasts 4–6 years before visible wear (patina, micro-creases, loosening of stitches) occurs. If worn occasionally and stored in controlled humidity, lifespan extends to 7–10 years. FKM rubber offers superior durability (8–12 years) under normal conditions, but degrades faster under prolonged UV exposure. Vegetable-tanned straps develop attractive patina over time, increasing character. Entrusting maintenance to a certified artisan (such as Casati Milano) significantly prolongs useful life.