Strap for Chronomat 40 GMT Six Nations France

The lug width of the Breitling Chronomat 40 GMT A323989B1C1A1 is 20 mm. This measurement can be verified using a digital calliper placed between the lugs at their narrowest point, or by fitting a trial strap before committing to a purchase.

For the Chronomat 40 GMT, vegetable-tanned calfskin straps are recommended for everyday wear, padded alligator for formal or business occasions, and vulcanised rubber for sporting or marine environments. All straps must have a 20 mm attachment width. A brushed stainless steel deployant clasp is the closing most consistent with the watch's original aesthetic.

To replace the strap, use a fine-tipped springbar tool. Insert the tip into the springbar slot between the lug and the strap, compress the bar and slide the strap out laterally. Repeat on the opposite lug. Fitting the new 20 mm strap follows the reverse procedure. Take care not to scratch the brushed steel lugs during the operation.

Yes. Any standard 20 mm strap is technically compatible with the Breitling Chronomat 40 GMT. Milano Straps and Casati Milano offer handcrafted aftermarket straps in calfskin, alligator, shell cordovan and rubber, made with selected materials and hand-stitched, available with a pin buckle or stainless steel deployant clasp.

Longevity depends on the material and frequency of use. A quality vegetable-tanned calfskin strap, regularly conditioned with leather cream, typically lasts 2–4 years with daily wear. Alligator, owing to the density of its fibre, tends to last longer if kept away from water. Shell cordovan is widely regarded as the most durable of all fine leathers. Frequent exposure to perspiration or moisture significantly shortens strap life.