Longines · Conquest

Strap for Conquest Automatic 29.5 Ceramic Diamond

Takes 15 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width15 mm
Case diameter30 mm
ReferenceL3.299.0.87.7 (aka: L32990877)
FamilyConquest
MovementLongines caliber L595 Hours, Minutes, Seconds | Date
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

The Conquest L3.299.0.87.7 (aka: L32990877), seen from the bench

The Longines Conquest features the L595 caliber with indication of hours, minutes, seconds and date. The watch has 15mm lugs and reference L3.299.0.87.7. The movement offers the essential functions in a classic three-hand configuration with date.

Frequently asked questions

What is the exact lug width of the Longines Conquest L3.299.0.87.7?

The lug width of this model is precisely 15mm, a non-standard dimension requiring specifically manufactured straps. Measurement must be taken perpendicularly between the two internal walls of the spring bar housing, completely excluding the spring bar itself. This precision is critical because 15mm does not correspond to common commercial sizes (16mm, 18mm), necessitating careful strap selection.

Which strap would you recommend for this 29.5mm Longines?

For a timepiece of this proportion and refinement, vegetable-tanned alligator represents the aesthetic continuity choice: the pronounced grain amplifies the perception of craftsmanship and the natural patina developed over time imparts tactile character. Alternatively, shell cordovan offers distinctive luminosity and extraordinary longevity, whilst box calf guarantees softness and sobriety. For more sporting use, natural rubber maintains elegance without sacrificing practicality.

How do you change the strap on the Longines Conquest L3.299.0.87.7?

Strap change requires a Spring Bar Tool or small flat lever. Position the watch on a stable surface with the spring bar exposed, gently insert the tool into the spring bar aperture to release it from the case, then extract the metal lug. Repeat on the opposite side. For installing the new strap, execute operations in reverse order, ensuring both springs click completely into position.

Can I use a generic 15mm aftermarket strap on this model?

Theoretically yes, but with caution. Many 15mm aftermarket straps are manufactured with slightly non-standard dimensional tolerances. It is advisable to verify that leather thickness and keeper width are compatible with case height. Milanostraps.it straps are specifically calibrated for this model, guaranteeing perfect fit and verified construction comfort. For those unwilling to assume risk, bespoke realisation with Casati Milano ensures maximum precision.

How long does a leather strap last on this watch with daily wear?

Longevity depends on material and tanning method. Vegetable-tanned alligator, naturally treated, comfortably withstands 10-15 years of daily use whilst maintaining structural integrity. Shell cordovan can exceed 15-20 years owing to the horse's dorsal fibrous membrane which absorbs moisture without degradation. Box calf, more delicate, typically maintains 7-10 years before replacement is required. Natural leather ageing is not wear but patina: the fibre remains intact whilst colour and texture transform, adding character to the strap over time.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only