Strap for Master Collection Date 25.5 Pink Gold - Diamond / MOP

The Longines Master Collection L2.128.9.87.3 features a lug width of 13mm, a specific dimension within the Longines feminine collection. This measurement represents the internal distance between the two case attachments where the strap is inserted. It is important not to confuse the lugs (the seats on the case) with the strap itself (the object that sits within them). To verify compatibility with a new strap, measure the lug width using callipers or a ruler positioned in the spring bar seat.

To enhance the elegance of the rose gold case, the ideal strap is in dark brown or black alligator. The regular texture of alligator scales creates a balanced visual dialogue with the guilloché dial without competing aesthetically. If you prefer a warm, supple approach, a cognac or burgundy calf strap introduces a chromatic element that amplifies the golden tone of the case. For more casual occasions, a vegetable-tanned leather strap offers character and a patina that improves over time, developing a subtle sheen at flex points.

To change the strap, begin by removing the watch from your wrist. Observe the attachments on the case side and identify the small slot where the spring bar sits (which protrudes from the strap lug). Obtain a specialist tool called a "spring bar tool" or a small flathead screwdriver. Insert the tool into the small side slot and gently press the internal pin downward while simultaneously leveraging with the screwdriver to extract the strap. Repeat on the opposite side. To install the new strap, align the spring bar with the case holes, press on both sides until the bar locks, and verify that the strap is secure.

Yes, it is possible to use aftermarket straps provided they strictly respect the 13mm lug width specification. Many standard straps are available in 12mm, 14mm or 16mm, so compatibility is not guaranteed. When purchasing a replacement strap, always verify that the supplier confirms the 13mm dimension. Bespoke handcrafted straps, made to order at ateliers such as Casati Milano, are the ideal solution to ensure perfect compatibility and superior construction quality, with conscious material selection and refined finishing.

The lifespan of a natural leather strap depends on usage intensity, care and tanning type. A high-quality alligator or calf strap, worn daily under normal circumstances, maintains functional integrity for 2–4 years before requiring replacement. If the watch is worn occasionally (2–3 times per week), longevity extends to 4–7 years. Vegetable-tanned leather tends to age visibly but in a rewarding way, developing a patina that increases aesthetic value. To extend strap life, avoid prolonged moisture exposure, do not immerse the strap in water, and periodically apply a protective emulsion. The Casati Milano atelier offers an 18-month guarantee on craftsmanship.