Strap for Speedmaster 321 38.6

The lug width is 19.00 mm, measured as the internal distance between the two attachment pins of the original strap. This width is standard for all Moonwatch models with 38–39 mm cases, including the 311.50.39.30.01.001 in Canopus Gold. Always verify directly on the instrument before ordering an aftermarket strap.

Black French alligator or natural vegetable-tanned calf are the most balanced choices. Alligator offers aesthetic contrast and decade-long durability, while natural calf develops a golden patina over time that dialogues masterfully with the golden case alloy. Shell cordovan is the premium option for those seeking an exclusive three-dimensional grain.

The change is done manually: you use a spring bar tool to compress the two elastic attachment pins under the case, remove the worn strap, then position the new strap and snap the pins into their seats. The operation requires a few minutes of practice. If you wish to avoid any risk, the Casati Milano atelier performs the change by appointment with made-to-measure straps.

All straps with 19 mm lug width are compatible. On milanostraps.it you will find a complete selection of 19 mm straps in various materials (alligator, calf, shell cordovan, rubber), customizable in sizes and finishes, ready for shipment. Each strap is tested for adherence to the Moonwatch pins.

A strap in artisanal-quality alligator or calf lasts 5–10 years with daily use, provided it is kept dry and protected from constant exposure to acidic perspiration. Vegetable tanning tends to last slightly less (4–7 years) but develops a patina that increases aesthetic value. High-quality rubber shows no aesthetic aging and maintains mechanical properties intact for 10–15 years.