Breitling
AVI A173151A1B1X1— lug 21mm

The Breitling AVI A173151A1B1X1 features a lug width of 21mm. This is a non-standard measurement compared to the more common 20mm or 22mm, so it is essential to verify this dimension before purchasing an aftermarket strap. A 20mm strap would sit too loosely between the lugs, while a 22mm strap would not fit at all. The correct size is 21mm at the lug end, typically tapering to 18–20mm at the buckle end.

For the Breitling AVI A173151A1B1X1, the most coherent choices with its aviator aesthetic are a coarse-grain calf leather strap or a matte black or tobacco-brown alligator strap. Aged calf leather develops an authentic patina that enhances the instrument-grade character of the dial. Alternatively, a RAF-striped NATO strap (khaki-burgundy-khaki) directly references the watch's aeronautical military heritage. For sporting use, vulcanised rubber with a microperforated surface provides breathability and durability. A brushed stainless steel deployant clasp completes the technical look without adding unnecessary bulk to the wrist.

The strap on the Breitling AVI A173151A1B1X1 is secured by springbars — small spring-loaded pins that connect the strap to the watch lugs. You will need a springbar tool with a fine tip: insert it into the lug hole or between the strap flange and the lug surface, compress the springbar, and slide the strap free. The process takes approximately two minutes per side and does not require case opening. We recommend working on a soft surface to avoid scratching the stainless steel case, and retaining the original Breitling springbars for correct fit and security.

Yes, high-quality aftermarket straps are available for the Breitling AVI A173151A1B1X1, provided they comply with the 21mm lug width specification. Milanostraps.it offers a curated selection of handcrafted 21mm straps in calf leather, alligator, and other premium materials. It is important to select straps with reinforced keeper loops to ensure correct tension across the lugs, along with springbars of appropriate diameter (generally 1.5mm for this format). Casati Milano straps are made to measure with contrast or tone-on-tone stitching, adaptable to both the technical and dressier expressions of the dial.

The lifespan of a leather strap depends on the type of hide, frequency of wear, and exposure conditions. A vegetable-tanned calf leather strap worn daily has an average lifespan of 18–36 months; a top-grade alligator strap, properly maintained, can exceed five years while retaining structural integrity and sheen. The main adversaries are perspiration, water, and UV exposure. To extend strap life: avoid prolonged moisture exposure, apply a neutral leather conditioner periodically, and loosen the buckle overnight. Casati Milano offers an 18-month production defect warranty on all straps.