Omega
Speedmaster Broad Arrow 3551.20.00— lug 20mm

The lug width of the 3551.20.00 is exactly 20mm. This dimension is specific to this reference and should not be confused with similar sizes (18mm or 22mm). To verify, position a caliper or ruler between the inner edges of both lugs: the distance must correspond to exactly 20mm.

The material depends on your usage and aesthetic preference. For formal contexts, we recommend genuine alligator with vegetable tanning, which develops a natural patina over time. For daily versatility, shell cordovan or quality calf with pronounced texture offers softness and adaptability. To maintain the Speedmaster's sporting spirit, structured rubber or technical fabric echoes the watch's professional heritage.

Strap change is performed by removing the spring bars that connect the lugs to the case. Use a dedicated tool—a spring bar removal tool—to release the mechanism without risking scratches on the case. Position the new strap and reinsert the spring bars, ensuring they are fully locked. If unsure, consult a professional watchmaker: the procedure requires practice to avoid aesthetic damage.

Yes, any strap with a 20mm lug width is compatible with the Broad Arrow 3551.20.00, provided the attachment spring bars are the same width. Online and at specialized ateliers—such as Casati Milano—you will find 20mm straps in various leathers, colors, and finishes. Always verify that the total length of the strap (band + buckle) suits your wrist size.

The lifespan of a leather strap depends on material quality, tanning method, and usage. A quality leather strap—alligator, shell cordovan, or superior calf—typically lasts 3–5 years with moderate daily wear. Vegetable tanning offers superior patina and durability compared to chrome tanning. With regular maintenance (cleaning, occasional conditioning) and rotation with other straps, it is possible to significantly extend longevity.