Omega · Seamaster 120M
Strap for Seamaster 120M Automatic 36.25 Stainless Steel / Yellow Gold / Champagne
Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
Straps for the Seamaster 120M 2301.11.00
Selected for the 20 mm lug width · workshop selection
Black Alligator Strap with Light Blue Edges€149
Red Alligator Strap Water Resistant€195
Green Rubberized Alligator Strap with Ecru Tribal Stitching€149
Military Alligator Green Strap€138
Hammered Calfskin Strap Light Blue€98
The Seamaster 120M 2301.11.00, seen from the bench
Frequently asked questions
What is the lug width of the Seamaster 120M 2301.11.00?
The lug width of the Seamaster 120M (reference 2301.11.00) is 20 mm. This measurement should be taken internally between the two vertical supports of the case where the spring bar is located. It is important not to confuse lug width with strap width: the 2301.11.00 requires straps specifically constructed for 20 mm width.
What is the best leather strap for the Omega Seamaster 120M?
For the Seamaster 120M 2301.11.00 in yellow gold and steel, we recommend vegetable-tanned alligator, which develops an extraordinary natural patina over time and harmoniously complements the two-tone combination. Alternatively, shell cordovan offers singular material density with accelerated patination capability, while box calf ensures daily versatility and certified durability.
How do I change the strap on my Seamaster 120M 2301.11.00?
To change the strap, you need to use a spring bar tool or remover to compress the spring bar located inside the lug. Once the spring is compressed, the old strap comes out easily. Insert the new 20mm strap by aligning the upper and lower lugs, then snap the spring bar back into place. If you lack experience, consult a specialized watchmaker.
Can I use compatible aftermarket straps on my Seamaster 120M?
Yes, the Seamaster 120M 2301.11.00 is fully compatible with quality aftermarket straps in 20 mm size. On milanostraps.it you will find a curated selection of artisanal straps in alligator, calf, shell cordovan and rubber, all tested for compatibility with your watch and customizable in size, initials and stitching color.
How long does a leather strap last on the Seamaster 120M?
The lifespan of a leather strap depends on the material and use. An alligator or calf strap in vegetable tanning, worn daily on a Seamaster 120M, has an average life of 5-8 years before requiring replacement. Shell cordovan, thanks to its superior density, can exceed 10 years. Rubber straps last 3-5 years. The Casati Milano guarantee on custom straps is 18 months, extendable for scheduled maintenance.
The next step
The right strap isn't chosen. It is built, together.
From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only

