Jaeger-LeCoultre
Master 1613401 (aka: Q1613401)— lug 19mm

The Jaeger-LeCoultre Master Perpetual Calendar 1613401 (Q1613401) has lugs with a 19mm opening. To verify this on your own watch, measure with a digital caliper the internal distance between the two lugs at the bottom of the case where the strap makes contact.

For a rose gold case with perpetual calendar, polished alligator leather represents the most coherent pairing with the formal aesthetic of this reference. Box calf leather is an elegant alternative for daily wear, while vulcanized rubber offers durability and comfort in less formal situations.

The Q1613401 strap is removed using a spring bar tool or small knife, applying leverage to the spring bar connecting the strap to the lug. The operation does not require professional tools but should be performed carefully on a soft surface to avoid scratching the rose gold case. If unsure, a trusted watchmaker can complete the change in a few minutes.

Yes. Aftermarket 19mm straps produced with standard attachment geometry are compatible with the Q1613401. Milano Straps offers a selection of handcrafted 19mm straps in various materials and finishes, with the option to order a bespoke model through the Casati Milano atelier for precise adaptation to the original lugs.

The lifespan of a leather strap depends on material quality, daily use, and exposure to sweat and humidity. A superior quality alligator strap, with periodic care and alternating use with other straps, can last three to five years while maintaining good structural integrity. Calf leather tends to develop a characteristic patina over time, which many enthusiasts consider part of the material's charm.