Jaeger-LeCoultre
Master 1612403 (aka: Q1612403)— lug 20mm

The Jaeger-LeCoultre Master Perpetual 1612403, also known as Q1612403, features a 20mm lug width. This measurement is verified by placing a millimeter gauge internally between the two lugs, measuring the net distance without including the lateral metal of the lugs themselves.

For a 40mm rose gold case with perpetual calendar, the ideal strap is alligator leather with fine scale grain in tobacco brown or burgundy wine tones. Box-calf leather in smooth finish is a more understated alternative. Both enhance the warm reflections of rose gold without competing with the richness of the dial.

The strap on the Master 1612403 is replaced using a fine-tipped spring bar tool or a dedicated lever tool, applying pressure to the end of the spring bar to disengage each side from the lug. This operation requires care to avoid scratching the rose gold case: if in doubt, it is advisable to entrust the work to a watchmaker or to the Casati Milano atelier.

Yes, any strap with a standard 20mm attachment is compatible with the Jaeger-LeCoultre Master Q1612403. Milano Straps offers a selection of artisanal 20mm straps — in alligator, calf, NATO, and rubber — crafted with materials and finishes suited to the level of the timepiece. Consult the complete selection of compatible 20mm straps at milanostraps.it.

The lifespan of a leather strap depends on the quality of the leather, frequency of use, and exposure to moisture and perspiration. A strap in high-quality alligator or calf leather, with regular use and proper care — avoiding direct water exposure and rotating between multiple straps — maintains structural and aesthetic integrity for 2-4 years. Casati Milano offers an 18-month warranty against manufacturing defects on all custom-made straps.