Strap for Master Collection 40 Date Stainless Steel / Silver-Diamond / Alligator XL

The lug width is 21mm. This is a specific measurement for this model and does not correspond to the most common ISO standards (20mm or 22mm). The recommended thickness varies between 4.5mm and 5.0mm for a fit true to the original Longines design intent.

The ideal strap depends on usage and personal preference. Alligator is the purist choice for formal elegance, vegetable-tanned calf offers fascinating natural ageing, NATO guarantees robustness in intensive contexts. The sunburst blue dial dialogues magnificently with dark brown alligator or cognac calf.

The change is straightforward: use a spring bar tool to gently extract the pins from the lugs. Align the new strap holes with the lugs, reinsert the pin until you feel the locking click. Ensure the 21mm lug width strap is proportioned correctly (thickness 4.5-5.0mm) for smooth operation.

Yes, absolutely. Aftermarket 21mm lug width straps are fully compatible, provided they respect the proportions (thickness 4.5-5.0mm). MilanoStraps offers a curated selection of 21mm straps in alligator, calf, NATO and rubber, customizable for your watch.

A quality leather strap (alligator, vegetable-tanned calf, or shell cordovan) lasts 3-5 years with regular daily use, considering proper maintenance (periodic cleaning, protection from salt water). Natural ageing is part of the charm, with patina and creases telling the personal history of the watch.