Strap for Seamaster 120M Automatic 36.25 Yellow Gold / Diamond / Blue

The lug width of the Seamaster 120M reference 2105.81.00 is 18mm. This dimension is specific to this model and represents the standard construction of the Seamaster 120M collection from the Seventies. Measuring the lug width correctly is essential: the width is determined by measuring internally the case lug opening, from the left inner shoulder to the right inner shoulder. An 18mm strap inserts perfectly without forcing or lateral play.

For a watch of this elegance, we recommend straps in brown alligator or dark brown, which enhance the warmth of yellow gold without weighing down the retro aesthetic. Alligator offers a fine grain structure and natural veining that dialogues perfectly with the refinement of the blue dial. Alternatively, a cognac-colored Norwegian calf with vegetable tanning creates an authentic vintage effect, with a patina that evolves over time. For a more contemporary interpretation, a NATO-style strap in navy blue fabric with a white side stripe echoes the chromatic dialogue of the dial.

Changing the strap is a simple operation that requires a spring bar tool. Position the watch with the lugs facing upward, insert the tip of the tool into the small hole beneath the lug to compress the internal spring, remove the spring bar, then slide off the old strap. Repeat the operation on the other side. Next, align the new strap, compress the spring with the tool and insert the bar. Ensure that both ends of the bar snap firmly into the anchor holes. This process does not require specialized skills, but extra care ensures a perfect result.

Absolutely yes. Any strap equipped with standard 18mm lugs is compatible with the Seamaster 120M. Compatibility depends on lug width (18mm), not on the brand. High-quality artisanal straps are often superior to original OEM products in terms of stitching workmanship, leather selection and finishes. Verifying that the lugs are of the correct width is the only technical requirement; the rest is a matter of aesthetic preference and construction quality.

The durability of an artisanal leather strap depends on leather quality, tanning method and intensity of use. An alligator or shell cordovan strap with vegetable tanning can last 5–10 years if subjected to moderate use and regular maintenance (periodic cleaning, protection from excess moisture). A calf of ordinary quality typically lasts 2–4 years. With intensive daily use and without protection, the lifespan is reduced. Factors such as sweat, chlorinated water and direct sunlight accelerate aging. Artisanal straps with vegetable tanning develop a natural patina that increases their aesthetic appeal over time, transforming wear into character.