Strap for Master Collection Big Date Small Seconds

The Longines Master Collection L2.676.4.78.5 features a lug width of precisely 21mm. This measurement corresponds to the internal space between the two lug bars that secure the strap to the case. The lug depth is approximately 8mm—a critical specification for selecting an aftermarket strap in terms of constructive thickness and wearing comfort.

The optimal choice depends on aesthetic preference and intended use. Alligator leather represents the purist solution with pronounced texture and certified durability. Shell cordovan offers a patina that evolves organically with time. Vegetable-tanned calf leather provides robust construction and ageing capability. For informal contexts, cotton NATO straps maintain discrete character and practical interchangeability. Rubber guarantees maximum water resistance but lacks the tactile depth inherent to quality leather.

Strap replacement is accomplished by removing the lug bars—the metal pins holding the strap in the case—using a dedicated pin removal tool (small screwdriver or specialist strap removal device) to prevent case scratching. Once the pin is extracted, the old strap separates readily. The new 21mm strap is inserted by aligning its lateral holes with the lug bar, which is then reinserted until fully secured. The procedure demands precision but requires no specialist equipment.

Yes, an artisanal 21mm strap offers complete compatibility from a constructive standpoint. Compatibility is guaranteed by lug width (21mm) and depth (approximately 8mm). It is essential to verify that the strap was manufactured with proportionate thickness specifications: straps that are too thin on wide lugs create inadequate tactile sensation, while excessively thick straps may compromise wearing comfort. Specialist ateliers such as Casati Milano construct to these precise specifications.

Lifespan depends on material, usage intensity, and maintenance practice. A superior-quality alligator strap guarantees 5–8 years of daily wear. Shell cordovan, constructed from denser leather, may last 7–10 years whilst developing a desirable patina. Vegetable-tanned calf leather has a typical lifespan of 4–6 years under constant stress. Periodic maintenance—neutral balm protection, drying after moisture exposure, rotational rest between straps—extends this duration significantly. Specialist ateliers provide warranties of up to 18 months on artisanal workmanship.