Strap for Cosmonaute Stainless Steel / Blue / Calf

The lug width of the Breitling Navitimer AB0210B4.C917.433X is 22mm. This measurement is standardised across the entire 43mm Navitimer line and should be measured with a digital calliper between the two lugs at the narrowest point, immediately adjacent to the case.

For the Navitimer B02 43mm, straps in vegetable-tanned Tuscan leather or alligator are the most coherent choice with the watch's aeronautical heritage. Leather develops a distinctive patina over time, while alligator lends a more formal register. Ballistic nylon NATO straps are ideal for intensive daily and sporting use.

To replace the strap, you will need a spring bar tool — a forked-tip instrument that compresses the ends of the spring bars housed within the lugs. It is advisable to rest the watch on a soft pad to avoid scratching the stainless steel case, and to work carefully around the machined lug ends.

Yes, any 22mm strap with a tapered tail to 20mm is technically compatible with the Breitling Navitimer AB0210B4.C917.433X. Milano Straps offers a curated selection of handcrafted straps in leather, alligator, shell cordovan and technical materials, all produced to 22mm lug width specifications with buckle or deployant clasp options.

The longevity of a leather strap depends on the quality of the tanning process, exposure to moisture and perspiration, and frequency of wear. A high-quality vegetable-tanned Tuscan leather strap, worn on rotation, can last between three and five years whilst retaining its structure and form. Milano Straps straps carry an 18-month warranty against manufacturing defects.