Strap for Hydroconquest Quartz 39 Two Tone Blue

The lug width of the Longines HydroConquest L3.640.3.96.7 is 20 mm. This measurement represents the distance between the case attachment holes. Purchasing a strap with 20 mm lug width ensures perfect compatibility with this model. We recommend measuring twice with a millimetre ruler to avoid purchasing errors.

For the Longines HydroConquest L3.640.3.96.7, we recommend alligator leather for sporty elegance with natural water resistance, or grained calf with vegetable tanning for humid environments and recreational diving. Nylon NATO straps offer technical practicality and quick cleaning, whilst vulcanised rubber excels for intensive underwater use. The choice depends on your primary context: daily-wear elegance, beach or professional diving.

To change the strap on your Longines HydroConquest L3.640.3.96.7, you will need a spring bar tool and a soft surface to protect the case. Locate the lateral lugs on the case, insert the tool tip into the lug hole, press gently inward to release the retaining spring, then remove the old strap. Mount the new strap ensuring both ends are fully seated in the lugs. Avoid excessive force to prevent damage to the case holes.

Yes, aftermarket straps with 20 mm lug width are fully compatible with the Longines HydroConquest L3.640.3.96.7. On milanostraps.it you will find a selection of artisanal straps customisable in leather (alligator, calf, shell cordovan), texture (leather, rubber, NATO), and colours. Casati Milano atelier also offers bespoke strap service with personal consultation and 18-month guarantee on craftsmanship.

A quality artisanal leather strap (alligator, vegetable-tanned calf) on the Longines HydroConquest L3.640.3.96.7 typically lasts 3–5 years with moderate daily wear, provided appropriate maintenance: avoid prolonged water immersion, dry quickly with a soft cloth after accidental exposure to moisture, occasionally apply conditioning balm. In salt-water environments or with frequent diving, lifespan reduces to 18–24 months; in such cases grained calf or vulcanised rubber are more sustainable choices. The patina that forms naturally on leather indicates longevity, not deterioration.