Strap for Hydroconquest Automatic 39 Black

The Longines HydroConquest L3.641.4.56.6 features a 20mm lug width. This measurement is taken by positioning a digital calliper between the inner lugs where the strap attaches to the case. Do not confuse lug width with the distance between the outer strap terminals, which will be slightly larger.

The ideal strap depends on intended use. For formal contexts, vegetable-tanned alligator in cognac or dark brown shades offers elegance and reliability. For daily versatility, softened calf leather develops beautiful patina over time. For water activities, a technical fabric NATO strap or FKM rubber ensures quick maintenance and fast drying. Shell cordovan represents the reserved choice for those seeking natural ageing and increasing internal reflections.

Strap replacement is performed via the spring bars connecting the strap to the case lugs. Use a dedicated tool (sprung bar tool or spring bar removal pen) to carefully lever the bars without excessive force on the case. Place the watch on a soft surface to prevent scratching. Gently remove the old strap, align the new strap's spring bars to the same depth, and verify that the attachment is secure with no lateral play.

Yes, any strap with a 20mm lug width is compatible with this model. 20mm straps are manufactured to international standards and require no adaptations. Simply verify the lug width by measuring between the inner spring bars. On milanostraps.it, the 20mm strap collection offers choices in alligator, calf, NATO and rubber, all ready to ship and customisable in length, initials and thread colour.

Durability depends on construction quality and usage patterns. A vegetable-tanned alligator or calf strap, worn daily with reasonable care, typically lasts 3-5 years before replacement. Gentle drying after water exposure, avoiding direct heat sources and annual conditioning with specialist products significantly extends strap life. FKM rubber or NATO fabric straps offer greater longevity (5-7 years) with minimal maintenance, making them ideal for extreme environments. Shell cordovan ages elegantly without losing function, requiring only regular cleaning and occasional treatments.