Strap for Conquest Quartz 36 Stainless Steel / MOP

The lug width of the Longines Conquest L3.378.4.87.6 measures 17 millimetres. This dimension is measured internally, from the inner edge of one hole to the inner edge of the opposite hole, using a digital calliper. Precise measurement is essential: even a 0.5 millimetre difference will result in excessive play or mounting failure. All our 17mm straps for this reference are verified to a tolerance of ±0.1 millimetres before dispatch.

For the stainless steel Conquest, we recommend alligator or vegetable-tanned anilina calf leather straps. Alligator emphasises the formal character, particularly when paired with a stainless steel deployante buckle. Calf leather offers superior softness and develops a natural patina over time that harmonises beautifully with the case's faceted surfaces. For humid environments, shell cordovan provides superior resistance without sacrificing elegance. NATO or rubber straps remain valid alternatives for sporty use, though the modest 36mm diameter requires proportionately restrained strap dimensions.

Strap changes are performed via spring bars inserted horizontally through the lateral case lugs. Procedure: 1) Obtain a spring bar tool or use a precision needle; 2) Gently depress the spring mechanism from beneath to release the bar; 3) Remove the bar from its hole; 4) Insert the new strap into the terminal loops; 5) Reinsert the spring bar. The operation requires dexterity and should be performed over a clean surface to prevent loss of the bars. If uncertain, we recommend assistance from a watchmaker or the Casati Milano atelier.

Yes, any strap with a certified 17 millimetre lug width is compatible, provided the spring bars are the correct diameter (typically 1.2–1.4 mm for vintage models). All our straps are tested for compatibility with the Conquest L3.378.4.87.6. Preliminary verification involves measuring the case's holes: if the internal distance measures exactly 17mm, any dedicated 17mm strap will mount without issue. We also recommend checking strap maximum thickness: for this model, thickness exceeding 4mm may cause excessive pressure on the lateral case edges.

Leather strap longevity depends on material and intensity of use. An alligator or shell cordovan strap with vegetable tanning typically lasts 5–7 years under moderate daily wear, extending to 10 years with occasional use. Anilina calf leather is slightly less resilient, usually 4–6 years. Lifespan increases if the strap is frequently removed (e.g., rotated with other straps) and stored in a dry environment away from heat sources. Natural leather ageing is aesthetic and does not compromise functionality. Artisanal straps from Casati Milano include an 18-month warranty against manufacturing defects; replacement is advisable beyond this period.