Strap for Premier Heritage B21 Chronograph Tourbillon Red Gold / Blue / Japan

The lug width of the Breitling Premier RB21203A1Q1P1 is 20mm. This measurement is taken with a calliper between the two lugs on the caseback side, measuring the internal distance. Respecting this dimension is essential to ensure correct spring bar fitment and strap keeper clearance.

For an 18kt red gold case, the most suitable options are polished alligator straps in bordeaux or cognac, which harmonise naturally with the warm tones of the metal. Alternatively, a black matte vegetable-tanned calfskin strap offers a sharp, formal contrast, while shell cordovan in chocolate develops a patina over time that complements the Premier's aesthetic perfectly.

The strap is removed using a spring bar tool to release the 20mm spring bars housed in the lugs. It is advisable to work on a soft surface to avoid scratching the red gold case. For models originally fitted with an integrated bracelet, aftermarket strap fitting requires spring bars with the correct diameter and length.

Yes. As the lug width of 20mm is a standard measurement in fine watchmaking, a wide range of quality aftermarket straps are available. Milano Straps offers a curated selection of handcrafted 20mm straps in alligator, calfskin and shell cordovan, verified for dimensional compatibility with the Premier's lugs. Casati Milano also provides a fully bespoke service.

Longevity depends on the material and frequency of use. A quality alligator strap, properly maintained with appropriate leather conditioner and kept away from moisture, can last between three and five years while retaining its structural and aesthetic integrity. Shell cordovan is particularly durable due to its dense fibre structure. Milano Straps backs its straps with an 18-month warranty against manufacturing defects.