Strap for Master Collection Power Reserve

The lug width of the Longines Master Collection L2.666.4.51.5 is 20mm. This measurement is taken between the two lug lugs, perpendicular to the case plane. A compatible strap must respect a thickness between 2.0 and 2.2mm to ensure correct insertion without mechanical play.

For the Master Collection L2.666.4.51.5, vegetable-tanned alligator represents the ideal luxury choice, as its natural texture amplifies the minimalist geometry of the case. Alternatively, calf leather offers daily versatility with natural patina development. Shell cordovan ensures compact grain and superior durability. Avoid overly casual materials such as NATO, which deviate from the formal aesthetic of the model.

Changing the strap on the L2.666.4.51.5 is performed by removing the lug pin (spring bar) with a dedicated tool, clicking the lateral mechanism and sliding out the old strap. Subsequently, insert the new strap by aligning the hole with the lug and releasing the pin until it clicks. Case disassembly is not required. If lacking specialised tools, consult a watchmaker or the Casati Milano atelier for damage-free intervention.

Yes, the Longines Master Collection L2.666.4.51.5 accepts 20mm aftermarket straps from numerous artisanal and industrial manufacturers. Straps from milanostraps.it, customisable in material, colour, initials and thread colour, guarantee assured compatibility. The Casati Milano atelier also creates custom straps with direct leather selection and 18-month warranty, ideal for those seeking constructive uniqueness and couture finishing.

The lifespan of a leather strap depends on the material and usage. A vegetable-tanned calf with daily wear has an average life of 18–24 months before replacement, developing a sought-after patina in the intervening months. Alligator and shell cordovan, more robust, can last 30–36 months if not exposed to prolonged humidity or intense perspiration. Leather stiffening and fibre thinning are signs of exhaustion. An FKM rubber or NATO strap lasts 3–4 years with minimal maintenance.