Strap for Master Collection Calendar

The lug width of the Longines L2.503.0.87.3 is precisely 20 millimetres. This dimension represents the internal space between the case lugs where the strap is housed. To verify it accurately, use a digital calliper measuring the internal distance between the case walls designated for the strap. A 20mm is specific to Master Collection models in 36mm format and is compatible exclusively with 20mm straps.

For the Master Collection L2.503.0.87.3, alligator leather with vegetable tanning represents the absolute choice of excellence. The regular texture of the leather, its capacity to develop patina with use, and its natural suppleness fully enhance the dress-watch character of the timepiece. Alternatively, a cognac-coloured calf box or burgundy shell cordovan offer aesthetic depth and certified durability over time.

The strap of the Longines L2.503.0.87.3 is secured using pass-through pins which are removed laterally. Position the watch on a soft cloth, use a spring bar tool (specific tool for watches) and gently push the pins from the side of the case. Once removed, slide out the old strap and fit the new one, ensuring the pin is centred and glides smoothly. Never force: if the pin resists, the strap is not correctly aligned.

Yes, it is possible. Aftermarket 20mm straps are fully compatible with the Longines L2.503.0.87.3, provided they respect the lug width and leather thickness (typically 1.4-1.8mm). The quality of the aftermarket strap is not subordinate to the watch brand: premium leather sourcing (African alligator, shell cordovan, full-grain calf) guarantees superior performance and longevity compared to ordinary OEM straps.

The lifespan of a leather strap depends on the tanning method, the type of leather and the intensity of use. A vegetable-tanned strap with good-quality alligator lasts on average 7–10 years in sporadic daily wear, developing pleasant patina over time. Superior-quality shell cordovan reaches 12–15 years. An ordinary calf box requires replacement every 4–5 years. Excessive exposure to moisture, unwashed perspiration and direct sunlight significantly shorten strap life.