Longines · HydroConquest

Strap for HydroConquest 41 Automatic Stainless Steel / Ceramic / Grey / Bracelet

Takes 21 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width21 mm
Case diameter41 mm
ReferenceL3.781.4.76.6 (aka: L37814766)
FamilyHydroConquest
MovementLongines caliber L888.2 hours, minutes, seconds | date
Year2018
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

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

Straps for the HydroConquest L3.781.4.76.6 (aka: L37814766)

Selected for the 21 mm lug width · workshop selection

All 21 mm straps →

The HydroConquest L3.781.4.76.6 (aka: L37814766), seen from the bench

The Longines HydroConquest mounts the automatic caliber L888.2 with indication of hours, minutes, seconds, and date. The case features 21mm lugs for the strap. The movement offers the essential functions for a mid-range dive watch.

Frequently asked questions

What is the lug width of the Longines HydroConquest L3.781.4.76.6?

The lug width is twenty-one millimetres (21 mm). This measurement is specific to this model and is taken by calculating the distance between the metal pins that connect the strap to the case. It is essential to verify this measurement with precision using a calliper, as even a minor deviation would result in incompatibility with available straps on the market.

Which strap should I choose for the Longines HydroConquest L3.781.4.76.6?

The choice depends on your intended use. For elegant contexts, alligator with vegetable tanning offers a natural patina that evolves over time. For daily versatility, black aniline calf leather ensures adaptability to any outfit. If you frequently use the watch in aquatic environments, an FKM rubber strap or a fabric NATO strap are the most pragmatic and durable solutions.

How do I change the strap on the Longines HydroConquest L3.781.4.76.6?

To change the strap, you must remove the lateral pins that secure the strap to the case. Use a dedicated tool (spring bar tool) to gently push the pins from the lateral holes. Once the pins are released, the old strap disengages; then insert the same pins into the new strap, ensuring they are completely seated. If you are not experienced, the change can be performed by an authorised watchmaker.

Can I use a compatible aftermarket strap with 21mm lug width?

Yes, any strap with a 21mm lug width is compatible with your HydroConquest L3.781.4.76.6, regardless of the manufacturing brand. However, it is advisable to verify that the pins are of the same length and diameter as the originals. Artisanal straps, made to measure with premium materials, guarantee perfect fit and superior longevity compared to standard industrial products.

How long does a leather strap last on the Longines HydroConquest L3.781.4.76.6?

Durability depends on the material and usage. An alligator strap with vegetable tanning, worn daily but not in prolonged humid environments, lasts approximately 8-12 years, developing a characteristic patina. Aniline calf has similar longevity but lower moisture resistance. An FKM rubber strap lasts 10-15 years if not exposed directly to intense UV radiation. Atelier Casati Milano guarantees 18 months on their straps, with the possibility of regeneration through stitching replacement.

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