Technical Archive

Breitling
Chronomat 40 GMT A32398B21C1A1— lug 20mm

Breitling Chronomat 40 GMT A32398B21C1A1: 20mm strap. Alligator, box calf, shell cordovan and rubber, cut and stitched in Milano. Choose your leather.

Breitling Chronomat Automatic GMT 40 NFL Buffalo Bills Edition

Artisanal Note

"This model requires a precise 20mm lug width to preserve the original sartorial balance."

Technical Specifications

Breitling A32398B21C1A1
Lug Width
20 mm

The essential strap measurement.

Browse 20mm straps →
Reference

A32398B21C1A1

Movement

Breitling caliber Caliber 32 Hours, Minutes, Seconds, Additional 24 Hour Hand (adjustable) | Date

The Heritage

The Chronomat 40 GMT is equipped with the Breitling 32 caliber with hour, minute, second, adjustable GMT hand and date functions. The case has a diameter of 40mm with 20mm lugs. The movement offers the display of a second time zone via the dedicated fourth hand.

FAQ

What is the lug width of the Breitling Chronomat 40 GMT A32398B21C1A1?

The lug width of the Breitling Chronomat 40 GMT A32398B21C1A1 is 20mm. This measurement is taken between the two parallel lugs at the point closest to the case, ideally using a digital calliper for accuracy. Only a 20mm strap will mount correctly and prevent damage to the lugs or spring bars.

What is the best strap for the Breitling Chronomat 40 GMT?

The best strap depends on the intended context. For formal or business wear, a vegetable-tanned alligator strap enhances the case geometry and underlines the manufacture character of the watch. Shell cordovan develops a personal patina over time, ideal for those seeking a strap that improves with use. For sport or marine environments, vulcanised rubber or ballistic nylon NATO straps are the most functional choices. All must have a 20mm lug width.

How do I change the strap on the Breitling Chronomat 40 GMT A32398B21C1A1?

To replace the strap, you will need a fine-tipped spring bar tool. By compressing the ends of the spring bar positioned between the lugs, the strap is released from the case. Care should be taken to avoid scratching the stainless steel case: protect the surface with a soft cloth and work on a stable surface. If in doubt, a watchmaker can perform the swap in a matter of minutes.

Are there aftermarket straps compatible with the Chronomat 40 GMT?

Yes, the aftermarket offers a wide selection of 20mm straps compatible with the Breitling Chronomat 40 GMT. Milanostraps.it stocks handcrafted straps in alligator, calfskin, shell cordovan and rubber, made to standards comparable or superior to the original. For optimal fit, straps with ends suited to the slightly curved lug profile of the Chronomat are recommended.

How long does a leather strap last on the Breitling Chronomat 40 GMT?

The lifespan of a leather strap depends on material quality, daily care and intensity of use. A quality alligator or shell cordovan strap, treated with appropriate leather conditioners and kept away from water and excessive perspiration, can last between 3 and 7 years while retaining a well-maintained appearance. Casati Milano straps carry an 18-month warranty against manufacturing defects.