Strap for Flagship 30 Stainless Steel - Pink Gold / White - Roman / Bracelet

The lug width of the Longines Flagship L4.374.3.91.7 is precisely 15mm. This measurement represents the distance between the lugs (the pins attaching the strap to the case) and is critical for compatibility. Always verify by measuring from the centre of one lug to the centre of the other, perpendicular to the case plane, to ensure a perfect fit.

For the Flagship L4.374.3.91.7 at 30mm, we recommend alligator in dark brown or black, which accentuates the elegant proportions of the case. Alternatively, vegetable-tanned calf leather offers versatility and develops a natural patina over time. For summer wear, cotton NATO or fluoroelastomeric rubber provide practicality without aesthetic compromise.

Strap replacement requires a spring bar tool or spring bar pin. Insert the thin tip into the small hole beneath the lug, gently pushing to compress the internal spring. This releases the strap from the case. Repeat on the opposite side. Installation of the new strap follows the reverse procedure. If uncertain, engage a qualified atelier such as Casati Milano.

Yes, the 15mm lug width is a well-established historical standard with abundant aftermarket options. Quality artisanal straps are available in premium leathers—alligator, shell cordovan, vegetable-tanned calf—as well as sporty alternatives in NATO and rubber. Always verify that the width is certified at 15mm and that the pins are compatible (standard stainless steel).

A quality leather strap, crafted with vegetable tanning or alligator, typically lasts 3–5 years with regular use, depending on sun exposure, humidity, and rotation frequency. Alligator generally outlasts other leathers. Periodic maintenance—gentle cleaning and conditioning with natural waxes—substantially extends lifespan. Casati Milano provides an 18-month warranty on all artisanal straps.