Jaeger-LeCoultre
Master Ultra Thin 1252520— lug 20mm

The Jaeger-LeCoultre Master Ultra Thin reference 1252520 is fitted with a 20mm lug width strap. This measurement is taken with a digital caliper positioned internally between the two lugs, excluding the metal of the lugs from the measurement.

For this 34mm rose gold model, a polished bordeaux or tobacco brown alligator strap represents the most coherent choice with the watch's character. The transverse grain of the scales complements the brushed surfaces of the case. Alternatively, smooth black calf leather ensures formal versatility. The ideal profile tapers from 20mm at the lug to 16 or 18mm at the buckle.

The strap is replaced using a spring bar tool—preferably one with a fine tip and plastic guard to avoid scratching the rose gold lugs. Compress the spring pin located between the lugs and remove the old strap, then insert the new one following the same procedure in reverse. The operation requires care: on gold cases, the risk of scratches during strap replacement is real. In case of doubt, it is advisable to consult a watchmaker or the Casati Milano atelier.

Yes. Any strap with a 20mm lug width and tapered profile is compatible with the Jaeger-LeCoultre Master Ultra Thin 1252520. Milano Straps offers a selection of artisanal 20mm straps made with premium materials—alligator, calf, NATO—available online or customizable through the Casati Milano atelier.

The lifespan of a leather strap depends on the quality of the leather, frequency of use, and exposure to perspiration and atmospheric conditions. An artisanal-quality alligator or calf strap, with regular but non-daily use, maintains its shape and patina for 2 to 4 years. Casati Milano straps are covered by an 18-month warranty against manufacturing defects. To extend the life of the strap, it is advisable to avoid prolonged water exposure and rotate between multiple straps.