Strap for Seamaster Master Co-Axial 39.5 Olympic Timekeeper Stainless Steel / White / Green

The Omega Seamaster 39.50mm, reference 522.32.40.20.04.005, features a 20mm lug width. This width is standard for the model and maintains ideal proportions between the case and the strap. Measuring from the first holes of the lugs, you will get exactly 20mm. Always verify this measurement before purchasing an aftermarket strap to ensure perfect compatibility.

For the Seamaster 39.50mm we recommend dark brown alligator (1.8mm thickness) for sport-elegant character, or vegetable-tanned calf for emphasizing the modernity of the caliber 8800. If you seek everyday versatility with the blue sunburst dial, natural patina Pueblo calf is the winning choice. For military contexts or outdoor weekends, Cordura NATO straps restore the historical identity of the collection.

Remove the old strap using a spring bar tool or a small flat screwdriver. Position the lever under the outer lug to lift the spring bar, then slide the pin laterally. Next, insert the new strap by aligning the lug holes with the pins and push until you hear the locking click. Make sure the strap is 20mm wide for optimal mechanical compatibility. If you prefer, Casati Milano offers a personalized fitting service.

All straps with 20mm lug width and standard 1.8mm pins are compatible. On milanostraps.it you will find a dedicated collection of 20mm straps in alligator, calf, shell cordovan and rubber. Each model is chosen to aesthetically match the blue sunburst dial and the satin-finished stainless steel case. We recommend leather with thickness between 1.8 and 2mm and robust construction to support the case weight (approximately 110g in steel).

A quality leather strap, subject to daily wear, typically lasts 3–5 years before requiring replacement. Durability depends on the material: shell cordovan and alligator have greater longevity (up to 7 years with care), while standard calf lasts 3–4 years. Factors such as humidity, sweat, frequency of use and sun exposure affect aging. Casati Milano guarantees 18 months on artisanal straps and offers preventive replacements before visible wear.