Strap for Speedmaster Professional Moonwatch MIR 365 / Yellow Gold

The lug width of the Speedmaster Moonwatch 3197.50.00 is 20 millimetres. This specific width is calculated to respect the proportions between the 42mm yellow gold case and the average European wrist. It is not possible to use straps of different widths (16mm, 18mm or 22mm) on this model.

For a Moonwatch in yellow gold, we recommend authentic alligator to elevate the strap to the rank of the case, dark shell cordovan to develop a deep patina, vegetable-tanned calf for a more modern sustainable approach, or rubber with a gold deployment clasp to maintain the authentic chronograph element. The choice depends on predominant use: evening versus daily wear.

To change the strap on the Moonwatch 3197.50.00, it is necessary to remove the spring bars that connect the strap to the case. These bars are extracted gently using a dedicated tool (spring bar removal tool) by pushing inward. Once the bars are freed from the old strap, you will insert the same bars into the new 20mm strap and secure them back to the case. We recommend this operation be performed by a professional watchmaker.

Yes, many quality aftermarket straps are available in the 20mm lug width and compatible with your Speedmaster Moonwatch. Online you can purchase ready-made straps in various finishes (alligator, calf, cordovan, rubber) customizable in sizes, initials and choice of stitching thread. For fully custom straps, the Casati Milano atelier creates bespoke pieces with personal selection of leathers.

The lifespan of a leather strap depends on the material and usage. Shell cordovan and artisanal vegetable-tanned leather maintain structural integrity for 5-7 years with moderate daily use. Authentic alligator typically lasts 4-6 years. Rubber has greater durability (8-10 years) but less evolutionary appeal. All quality straps benefit from a minimum 18-month warranty against manufacturing defects.