Strap for Conquest Quartz 25 Diamond

The lug width (ansa width) of the Longines Conquest L3.158.0.87.6 is 12 millimetres. This is a non-standard measurement, considerably smaller than industrial norms of 18mm, 20mm, or 22mm. It is essential to verify this specification before purchasing a strap, as incorrect sizing will result in lateral overhang or gaps that compromise both aesthetics and practical wearability.

For an elegant, feminine timepiece such as the Conquest, an alligator leather in neutral tones (dark brown, grey, black) accentuates its formal vocation. Alternatively, vegetable-tanned calf leather with fine grain offers a natural patina that ages gracefully. For more versatile contexts, an FKM rubber strap or nylon NATO maintains adaptability without compromising the steel case's refinement.

The strap is changed by extracting the spring bars that secure the lug to the underslung seat. Using a dedicated spring bar tool, depress the small plunger to release the bar, then withdraw the old strap. The new 12mm strap is inserted by aligning the lug with the case shoulders, ensuring the bar clicks fully into position. The operation requires care to avoid scratching the case finishing.

Yes, high-quality aftermarket 12mm straps are available from specialist artisanal makers. Options include alligator, calf, shell cordovan, and rubber, all sized precisely to 12mm lug width. Always confirm the lug width specification and verify total strap length is proportionate to wrist dimensions, avoiding excessive overhang or undersizing at the case flanks.

A quality leather strap (alligator or natural calf) subjected to moderate daily wear maintains structural integrity for approximately 5-7 years before replacement becomes necessary. Surface patina and micro-creasing enhance aesthetic character, though mechanical resistance—specifically stitch integrity and buckle attachment points—gradually diminishes. Proper maintenance (protection from excessive moisture, prompt drying after accidental wetting) substantially extends strap longevity.