Omega
Speedmaster Broad Arrow 3654.20.31— lug 20mm

The lug width of the Speedmaster Broad Arrow 3654.20.31 is 20mm. This measurement corresponds to the distance between the lugs of the case (measured from the inner shoulder of one lug to the other) and is the fundamental parameter for choosing a compatible strap. Always verify this measurement before ordering a replacement strap, also consulting the original Omega strap supplied with the watch.

For the 3654.20.31, alligator (hazel brown or black), shell cordovan (for those who love leather that ages over time), and vegetable-tanned calf are ideal. Alligator creates a natural aesthetic harmony with the rose gold case, while cordovan offers superior resistance. Vegetable-tanned calf is also excellent for a patina that evolves over time, just like the metal. More casual choices include NATO fabric or technical rubber, useful for sports or travel.

The change requires a spring bar tool (a tool with a double tip). Gently insert one tip into the slot of the spring bar, lift the strap to fully expose the bar, extract the bar from the opposite seat. The new strap is inserted by aligning its holes to the bars, then reposition the bars in the lugs. Avoid forcing to prevent damage to the case lug seat. If uncertain, contact a trusted workshop or the Casati Milano atelier for a strap change with professional consultation.

Any strap with a 20mm lug width is compatible, provided that the lug seat (the area that accommodates the strap) is constructed with proportions consistent with the model. The handcrafted straps from milanostraps.it are specifically designed for this width and customizable in leather, color, initials, and type of buckle or deployant clasp. It is important to choose quality materials (alligator, cordovan, calf) to ensure durability and aesthetics commensurate with the watch.

Longevity depends on the material, usage, and care. Quality alligator typically lasts an average of 4-6 years with moderate daily use. Shell cordovan can exceed 6-8 years thanks to its density. Well-crafted vegetable-tanned calf averages 3-5 years. Factors such as sun exposure, humidity, and perspiration accelerate wear. Handcrafted straps from Casati Milano include an 18-month warranty and can be regenerated or replaced over time, maintaining aesthetic coherence with the watch.