Strap for Master Collection 34 Moonphase Stainless Steel / Silver / Alligator

The lug width (distance between the centres of the lugs) of the Longines Master Collection L2.409.4.78.3 is 18 millimetres. To verify this measurement correctly, measure from the centre of one lug pin to the centre of the other pin on the same lug: 18 millimetres is the standard for this reference. A strap with a different width will either not fit into the lugs or create micro-movements that damage both the case and the strap.

For the 34-millimetre L2.409.4.78.3 with a silver-brushed dial, noble leather options are recommended: alligator (with a regular texture that dialogues with the case geometry), shell cordovan (naturally ageing patina), or vegetable-tanned calf (smooth surface with colours that shift towards golden ochre). A cognac or dark brown alligator is the classic choice; a champagne-coloured calf offers visual lightness; a deep burgundy shell cordovan adds formal character. Each material communicates a distinct aesthetic identity whilst remaining coherent with the restrained philosophy of this Longines.

The procedure requires a specific tool: a spring bar tool, which gently lifts the small metal pin (spring bar) that holds the strap inside the case lugs. Insert the tool into the slot, push gently inward to release the pin, then extract the old strap. Align the new strap's holes with the pin positions and push the pin inward with the tool until it clicks into the locked position. If you are uncertain about the procedure, the Casati Milano atelier offers this service during strap purchase.

No. An 18-millimetre strap is compatible exclusively with watches that have an 18-millimetre lug width. The Longines Master Collection L2.409.4.78.3 requires exactly 18 millimetres: straps for 16 or 20 millimetres will not fit correctly. It is always advisable to verify the lug width of your specific timepiece before ordering an aftermarket strap.

The lifespan of a leather strap depends on the material and usage patterns. A quality alligator or shell cordovan strap, with daily wear and proper care (protection from direct water, drying after perspiration, avoiding permanent creases), typically lasts 4–6 years before replacement is needed. Vegetable-tanned calf has comparable longevity if subjected to similar care. A synthetic or FKM rubber strap lasts longer (8–10 years) but gradually loses elasticity. The Casati Milano atelier guarantees 18 months on custom-made straps and recommends periodic maintenance to extend the useful life of natural leather.