Longines
HydroConquest L3.781.3.06.9— lug 21mm

The lug width is precisely 21 millimetres. This intermediate dimension is model-specific and ensures harmonious proportions with the 41mm case. To verify compatibility, measure the distance between the case lugs using a digital calliper: the value must match exactly 21mm.

Alligator leather with vegetable tanning offers maximum temporal elegance and ages beautifully. For frequent sports and water use, a medical-grade rubber strap guarantees resistance to salt water and chlorine. A grained calf leather represents the ideal compromise: daily robustness with a patina that evolves over time.

Remove the watch from the original strap using a specific tool (removable pin or flat-head screwdriver) to push the lug pins toward the inside of the case. The pins are positioned laterally, one on each side. Insert the new strap by aligning the holes with the pins and verify that the strap adheres perfectly without lateral play. This operation requires precision: professional watchmaker assistance is recommended if you lack experience.

Yes, any strap with a 21mm lug width is mechanically compatible. However, ensure that the strap thickness (measured at the base where it inserts into the pin) does not exceed 3mm: otherwise it will not adhere correctly to the lugs. High-quality artisanal straps always guarantee this tolerance.

A quality leather strap, subjected to vegetable tanning and constructed with careful quality control, lasts on average 18–36 months with daily wear. Frequent exposure to water (swimming pool, shower, sea) reduces lifespan to 12–18 months. Medical-grade rubber, by contrast, maintains structural integrity for 3–5 years even in extreme aquatic environments.