Jaeger-LeCoultre
Master Ultra Thin 1258401— lug 20mm

The Jaeger-LeCoultre Master Ultra Thin 1258401 is fitted with 20mm lugs. This is the standard width for this reference in the Master Ultra Thin family with a 34mm case. For confirmation, it is always advisable to measure the internal distance between the lugs with a caliper before ordering a replacement strap.

For the Master Ultra Thin 1258401, an alligator strap with a matte or semi-glossy finish is the most coherent choice with the model's DNA: it enhances the moon phase complication and in-house caliber without adding weight to the ultra-slim case profile. Smooth calf leather is an excellent alternative for daily wear. Both should feature a progressive taper from 20mm to 16-18mm and restrained thickness at the lug area.

The strap on the Master Ultra Thin 1258401 is secured to the lugs via standard 20mm spring bars. To replace it, you only need a fine-pointed spring bar tool to remove the spring bars and insert the new strap. The operation takes less than a minute and requires no service intervention, provided you use an appropriate tool to avoid scratching the steel case.

Yes, the straight lug geometry and 20mm standard of the Master Ultra Thin 1258401 ensure full compatibility with 20mm aftermarket straps available on the market. Milano Straps offers a selection of artisanal compatible straps, available online, and Casati Milano's bespoke service for those seeking custom craftsmanship with direct leather selection at the atelier.

The lifespan of a leather strap depends on material quality, daily use, and exposure to perspiration and atmospheric conditions. A high-quality alligator or calf leather strap, with regular but not exclusive use, has an average life of 2-4 years before the leather shows signs of structural wear. Casati Milano straps are covered by an 18-month warranty against manufacturing defects. To extend durability, it is advisable to rotate between two straps and store the unused one away from direct heat sources.