Strap for Seamaster Planet Ocean 600M Co-Axial 42 Stainless Steel / Black / Alligator

The lug width of the Seamaster Planet Ocean 2901.50.37 is 20mm. This dimension represents the distance between the inner lugs of the case. It is essential to measure your previous strap between the lugs themselves, not on the outer surface, as even 1mm discrepancy will alter the final aesthetics on a 42mm case.

The choice depends on intended use. For elegance and fascinating patina: cognac or black alligator, or shell cordovan. For authentic marine resistance: vegetable-tanned calf (moderate water resistance, natural aging) or structured rubber (FKM) if you plan regular diving. NATO is a backup and sporty solution. The blue ombré dial pairs beautifully with black alligator (contrast) or natural cognac calf (tonal harmony).

Remove the spring bars that pass horizontally through the case lugs. Use a spring bar tool (dedicated lever for spring bars): insert the thin end into the spring bar notch, gently lift to release the spring, then slide off the old strap. Repeat on the other side. Replace with the new strap by aligning the holes with the spring bars, then reinsert the spring bars and verify they are completely seated. If unfamiliar with the procedure, entrust installation to Casati Milano for bespoke service.

Any strap with a 20mm lug width is mechanically compatible with the Seamaster Planet Ocean 2901.50.37. On milanostraps.it you will find Italian artisanal straps designed for this size: alligator, vegetable-tanned calf, shell cordovan, NATO and rubber. All available in standard configuration or customized in length, thread color and initials at the Casati Milano atelier.

A quality alligator or calf strap, worn daily, maintains functionality and aesthetics for 3-5 years. Shell cordovan, due to superior density, reaches 5-7 years. Lifespan increases if you limit exposure to salt water and direct sunlight. The patina that develops is prized: darkening, light creasing and shoulder wear represent positive aging. A rubber strap, by contrast, lasts 8-10 years with minimal maintenance (rinsing after salt water immersion).