Longines
Flagship L4.374.3.91.7— lug 15mm
Longines Flagship L4.374.3.91.7: 15mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.
Artisanal Note
"This model requires a precise 15mm lug width to preserve the original sartorial balance."
Technical Specifications
Longines L4.374.3.91.7The essential strap measurement.
Browse 15mm straps →L4.374.3.91.7
Longines caliber L592.5 Hours, Minutes, Seconds | Date | Chronometer
The Heritage
FAQ
What is the exact lug width of the Longines Flagship L4.374.3.91.7?
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.
What type of strap pairs best with the Longines Flagship L4.374.3.91.7?
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.
How do you change a strap on a watch with 15mm lugs?
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.
Are there aftermarket straps compatible with the Longines Flagship L4.374.3.91.7?
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).
What is the typical lifespan of a leather strap on a Longines Flagship?
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.