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 width
Straps for the HydroConquest L3.781.4.76.6 (aka: L37814766)
Selected for the 21 mm lug width · workshop selection
Hammered Pink Strap with Ecru Stitching€98
Hammered calfskin strap in cuoio€98
Hammered Calfskin Strap Light Blue€98
Millennium Green Alligator Strap€195
Matte Black Alligator Strap€195
The HydroConquest L3.781.4.76.6 (aka: L37814766), seen from the bench
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.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only
