Strap for Chronomat 40 GMT Six Nations Wales

The lug width of the Breitling Chronomat 40 GMT A323988B1K1A1 is 20mm. This measurement is taken between the inner surfaces of the case lugs and is the essential parameter for selecting a compatible strap. All 20mm straps in the Milano Straps catalogue are directly compatible with this reference.

The most suitable materials for the Chronomat 40 GMT are vegetable-tanned alligator leather — ideal for hybrid business-casual use — smooth calf leather for a more understated profile, and vulcanised rubber for sporting contexts. A nylon NATO strap references the model's aviation origins. The choice depends on intended use and dial colour: dark dials pair particularly well with cognac and tobacco-brown tones.

The strap is removed using a springbar tool: the fine-tipped instrument is inserted into the lug hole to compress the spring bar and release the strap. Care must be taken to avoid scratching the case. Alternatively, a watchmaker or the Casati Milano atelier can perform the swap with professional fitting included.

Yes. Any strap with a 20mm lug width is compatible with the Breitling Chronomat 40 GMT A323988B1K1A1, provided a standard spring bar is included or already fitted. Milano Straps offers a wide selection of handcrafted aftermarket straps in various leathers and materials, all produced with straight 20mm ends suited to this model.

The lifespan of a leather strap depends on the material, tanning quality, and daily use. A high-quality alligator or shell cordovan strap, with regular care and alternating wear, can last between three and six years. Calf leather straps tend to have a shorter life, typically one to three years. Casati Milano provides an 18-month warranty against manufacturing defects on all atelier straps.