Strap for Master Collection 42 Chronograph Calendar Stainless Steel / Blue / Strap

The lug width of the Longines Master Collection L2.773.4.92.0 is 20mm. This measurement represents the internal distance between the two lugs of the case and is crucial for compatibility with any aftermarket strap. Always measure from inner edge to inner edge of the lugs, perpendicular to the case plane, using a digital calliper for maximum accuracy.

For this automatic chronograph, alligator is the most stylistically coherent choice: its fine, natural texture pairs perfectly with the understated elegance of the 42mm stainless steel case. Alternatively, vegetable-tanned calf leather offers resilience and develops a rich patina over time. For less formal contexts, a NATO strap in cordura or a hi-tech rubber strap provides practicality without compromising overall aesthetics.

Changing the strap requires a springbar tool (a device to remove the spring bar). Position the tool in the slot at the base of the lug, apply gentle pressure to compress the internal spring, then extract the bar from its seat. Repeat for both sides. To install the new strap, align the holes with the lugs and reinsert the bar until it clicks into place. If you prefer to avoid the risk of scratching the case, consult a specialist watchmaker or Casati Milano for professional replacement.

Yes, the 20mm lug width is an established standard in the Master Collection design, so many aftermarket strap options are available from specialist suppliers, such as milanostraps.it. You can order ready-to-ship 20mm pre-made straps or personalise them in dimensions, initials and thread colour. Casati Milano also offers the possibility of bespoke creations, with direct leather consultation and 18-month warranty.

A quality leather strap (alligator, calf, shell cordovan) rotated regularly with at least one other strap can last 4–6 years of moderate daily wear. Longevity depends on factors such as frequency of wear, ambient humidity, direct sun exposure and maintenance. A vegetable-tanned strap tends to age gracefully, developing a desirable patina. Casati Milano guarantees its handcrafted straps for 18 months, a warranty that protects against manufacturing and material defects.