Longines
HydroConquest L3.370.4.56.6— lug 16mm

The lug width of the Longines HydroConquest L3.370.4.56.6 is 16mm. This precise measurement ensures compatibility with straps specifically dimensioned for this width. To verify the correct lug width, position a digital calliper inside the lugs—the metal extensions protruding from the case—and measure the internal distance between them. Manufacturing tolerances maintain 16mm as the standard, guaranteeing reliable compatibility with straps designed for this measurement.

Strap selection depends on usage and aesthetic preferences. For refinement without compromise, alligator is the natural choice: fine texture and regular patterning convey sophistication, whilst the robust structure resists wear over time. Vegetable-tanned nappa calf offers suppleness and develops unique patina with age. For demanding marine environments, vulcanised rubber guarantees grip even when wet. For a casual-sports aesthetic, robust canvas NATO is versatile and dependable. All these materials are available in 16mm versions compatible with your model.

To change the strap, use a spring bar tool—the specialised instrument with a bifurcated tip. Position the watch on a stable surface with one of the lugs facing upward. Insert the tool's tip into the small hole on the inside of the lug, gently lifting the small metal spring (spring bar) that holds the strap in place. Once the spring retracts, the strap will slide free. Repeat the procedure on the other side. To install the new strap, align the strap's holes with the lugs, insert the spring bar into the hole and press gently until you hear a locking click. Ensure both sides are firmly engaged before wearing the watch.

Yes, any strap with a 16mm lug width is compatible with the Longines HydroConquest L3.370.4.56.6. Milano Straps offers an extensive selection of artisanal straps in various leathers—alligator, calf, shell cordovan—and technical materials such as rubber and NATO, all dimensioned specifically for 16mm. Compatibility is guaranteed by the precision of the lug width measurement, which ensures perfect engagement with the model's lugs. Using high-quality aftermarket straps does not compromise watch functionality; rather, it enables broader and more considered aesthetic personalisation.

The lifespan of a leather strap depends on material quality, intensity of use and environmental exposure. A premium exotica strap, such as alligator or shell cordovan, subjected to vegetable tanning, can last 3 to 5 years of regular use whilst developing an appreciated patina that enhances aesthetics over time. A nappa calf strap tends to require more frequent replacement—around 2 to 3 years—due to lower structural robustness. Constant exposure to moisture, perspiration and sunlight accelerates leather ageing. Milano Straps provides straps with an 18-month warranty and offers reconditioning and bespoke replacement services at the Casati Milano atelier.