Jaeger-LeCoultre
Master 1618420 (aka: Q1618420)— lug 20mm

The Jaeger-LeCoultre Master 1618420 (Q1618420) is fitted with lugs with a width of 20mm. This is the measurement to use when selecting any compatible aftermarket strap, which can be verified with a caliper positioned internally between the two lugs in contact with the case.

For a perpetual calendar complication like the Q1618420, a Louisiana alligator strap with polished or semi-polished grain is the most coherent choice with the watch's prestige. Box calf leather represents a more contemporary alternative, while vulcanized rubber suits less formal uses. All must have a 20mm lug width.

Replacing the strap on the Q1618420 requires a fine-tipped or fork spring bar tool to remove the spring bars from the lugs. It is recommended to work on a soft surface to protect the steel case and dial surfaces. If in doubt, it is advisable to contact a watchmaker or the Casati Milano atelier for professional service without risk of scratches.

Yes. Any 20mm aftermarket strap with straight or slightly curved ends is compatible with the Jaeger-LeCoultre Master Q1618420. On milanostraps.it a selection of 20mm straps is available in various materials and finishes, all verified for geometric compatibility with the lugs of this model.

The lifespan of a leather strap depends on the material, frequency of use, and exposure to sweat and humidity. A quality alligator strap, with proper care, lasts an average of 2-4 years with daily use. Box calf develops an interesting patina over time but is more sensitive to humidity. Casati Milano straps are covered by an 18-month warranty against manufacturing defects.