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

The Seamaster 120M 2105.11.00 is fitted with an 18 millimeter lug width. This measurement was the Omega standard for sport models from the 1970s and 1980s series. To verify compatibility, position the watch horizontally and measure the distance between the two lateral lugs of the case: it must be exactly 18 mm. Do not confuse lug width with case diameter: these are two independent parameters.

For a Seamaster 120M in yellow gold from the 1970–1980 decade, we recommend alligator or burgundy calf, both in vegetable tanning. Alligator provides a natural texture that harmonizes with the patina of the gold: the pattern of the scales recalls the artisanal origin of the piece. Deep burgundy calf, on the other hand, offers a more austere and subtle elegance. Avoid synthetic straps: they clash with the nobility of the precious metal. A quality FKM rubber is acceptable only if your Seamaster is destined exclusively for underwater use.

Changing the strap on a vintage precious metal watch requires specific tools. Obtain a thin spring bar tool with a pointed tip, never flat. Insert the tip into the lateral hole of the lug from the rear, apply gentle downward pressure to release the spring, then extract the suspension bar. Repeat on the other lug. Gold is soft: any abrupt movement leaves micro-scratches. We recommend entrusting this operation to a professional watchmaker or using the strap-changing service offered by Casati Milano, where craftsmen operate with precision instruments and decades of experience on valuable pieces.

Yes, provided the strap is specifically manufactured for 18 mm lug width. Not all manufacturers respect tolerances: a strap even 0.5 mm too narrow or too wide creates play or damaging stress on the case. Our straps are constructed with ±0.1 mm tolerance on the lugs, ensuring perfect fit. Additionally, we recommend straps made with full-grain leather or metal lugs, never stamped plastic: the latter will deteriorate over time and the strap will detach.

A strap in vegetable-tanned leather (alligator or quality calf) subjected to moderate wear (worn 3–4 times a week, no salt water) lasts on average 3–4 years before the leather begins to fail near the lugs. Wear accelerates with direct exposure to sunlight, intense heat, and humidity from pools or the sea. Our straps come with an 18-month warranty against manufacturing defects. Careful study of the leather's patina is part of the beauty of the piece: every scratch becomes history. When the leather begins to break down, replacement is not a defeat, but an opportunity to choose a different tone and renew your aesthetic relationship with your Seamaster.