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

The Omega Seamaster 120M 2105.15.00 uses an 18 millimeter lug width. This measurement is specific to Omega chronographs from the 1970s generation and represents the ergonomic standard for the 36.25 millimeter case diameter. Verify the spring bar opening measurement before purchasing a strap: the tolerance margin is ±0.5 millimeters.

To enhance the 18K yellow gold, we recommend vegetable-tanned alligator in cognac or dark brown shades, which creates sophisticated contrast without competing with the case's luminosity. Vegetable-tanned calf is the alternative for those preferring superior comfort and softness. Dark burgundy shell cordovan offers a patina that ages beautifully over time. Avoid steel straps that dilute the precious identity of the watch.

The Seamaster 120M features standard removable spring bars. Using a spring bar tool, position the instrument from inside the case in the small hole at the base of the spring bar, gently compress the spring and extract the bar outward. Repeat on the other side. Reverse the procedure with the new strap, ensuring the spring bar is fully inserted in the hole and the spring returns to compression. Do not force: a correctly mounted spring bar enters with controlled pressure.

Yes, the 2105.15.00 accepts any quality strap with an 18 millimeter lug width. However, we advise caution in material selection: yellow gold requires straps that respect the piece's heritage and intrinsic elegance. Inexpensive straps or those with flashy finishes contrast with the watch's status. Artisanal leather straps with vegetable tanning maintain aesthetic coherence and guarantee superior longevity.

A quality artisanal leather strap lasts on average 3-5 years with daily wear, depending on climate, humidity and maintenance frequency. Alligator and shell cordovan with vegetable tanning offer superior durability precisely because they improve with time, developing protective patina. Calf leather requires more maintenance but retains its softness intact. We recommend rotating two straps to extend the useful life of each and protect your investment in the precious watch.