Strap for Master Collection 40 Date Stainless Steel / Black-Roman / Alligator

The lug width of the Longines Master Collection L2.793.4.51.7 is 21mm. This measurement represents the physical space between the two metal lugs on the case and is essential for selecting a compatible strap. You can verify this specification using a digital calliper or by consulting the official Longines warranty certificate provided with the watch.

For the Master Collection L2.793.4.51.7 with midnight blue dial, we recommend three options: alligator leather in vegetable tanning with dark brown tone (balanced elegance and durability), smooth calf leather in white or cognac (versatility in pairings), or shell cordovan for those seeking natural patina development and superior moisture resistance. A black NATO strap remains the ideal alternative for sporty or casual contexts. Your choice depends on intended usage environment and frequency of wear.

The L2.793.4.51.7 strap is changed using a specific tool called a spring bar remover. Position the remover in the small groove on the case lug, gently compress the tiny metal pin (spring bar) and remove the old strap. Repeat on the other side. To fit the new strap, align the holes with the metal pin and press until you hear a click of confirmation. If you are not experienced with this procedure, consult a professional watchmaker or our Casati Milano atelier.

Yes, any strap with a 21mm lug width is compatible with the L2.793.4.51.7. At milanostraps.it you will find a wide range of artisanal straps in leather, alligator, shell cordovan and fabric, all crafted and tested for this specific lug width. The build quality of an aftermarket strap can even exceed the original Longines strap, thanks to carefully selected materials and tailored construction techniques.

A quality leather strap, made from vegetable tanning (as with milanostraps.it straps), has an average lifespan of 4-5 years with daily wear and minimal maintenance. Longevity depends on factors such as sun exposure, ambient humidity, frequency of wear and care. Shell cordovan, thanks to its fibrous structure, can last up to 6-7 years. To extend strap life, we recommend avoiding prolonged water exposure and periodically applying a protective balm based on beeswax.