Strap for Master Collection Retrograde

The lug width of the L2.715.4.71.6 is precisely 20 millimetres. This measurement represents the internal space between the lugs where the strap is fitted. To verify it, use a digital calliper and measure the distance between the two internal lug shoulders: the correct value must be exactly 20 mm. Any compatible strap must respect this dimension to guarantee proper fitting and security.

The material choice depends on intended use. For formal occasions, hand-stitched alligator with vegetable tanning or polished calf leather are elegant options that reflect the geometric clarity of the case. For daily wear, shell cordovan develops a natural patina over time, improving with age in line with Longines philosophy. For maximum versatility, a cotton NATO strap or FKM rubber strap allows rapid transitions between casual and semi-formal contexts without compromising durability.

Strap replacement is carried out via the spring bars. Use a dedicated spring bar tool to compress the spring mechanism on one side, extracting it from the lug hole. Once the spring bar is removed, the original strap disengages. Insert the new 20 mm strap, aligning the holes laterally, then reinsert the spring bar whilst compressing it until you hear a click of security. Verify that the spring bar is fully locked in both lugs before wearing the watch.

Yes, any 20 mm lug width strap is compatible with the L2.715.4.71.6, provided it respects this exact measurement. Quality aftermarket straps in alligator, calf leather, shell cordovan or synthetic materials offer the same reliability as original Longines straps. It is essential to verify the exact lug width before purchase: an error of 0.5 mm can result in fitting problems or excessive looseness.

A quality leather strap, such as alligator or vegetable-tanned calf, typically lasts 5-7 years of daily wear, depending on exposure to moisture, perspiration and sunlight. Shell cordovan tends to last slightly longer due to its greater thickness and inherent durability. Regular maintenance—gentle cleaning with a damp cloth and periodic treatments with natural wax—extends strap lifespan. Conversely, an FKM rubber strap resists for 10-12 years, although rubber may lose elasticity over time.