Omega · Seamaster Diver 300M
Strap for Seamaster Diver 300M Master Co-Axial 42 America's Cup 2024
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 Diver 300M 210.30.42.20.04.002
Selected for the 20 mm lug width · workshop selection
Military Red Alligator Strap with Blue Stitching€183
Black and Red NATO Strap — Military Heritage€183
Black Crocodile Military Strap with Blue Stitching€183
Black Calfskin NATO Strap 20mm€80
Dark Brown Calfskin Military Strap€80
The Seamaster Diver 300M 210.30.42.20.04.002, seen from the bench
Frequently asked questions
What is the lug width of the Omega Seamaster Diver 300M 210.30.42.20.04.002?
The lug width is 20mm. This measurement is standard for the 210.30.42.20.04.002 model and is essential to ensure complete compatibility with the strap. It is not possible to use lugs of different sizes without compromising stability and wearing comfort.
What is the best strap material for the Seamaster Diver 300M 210.30.42.20.04.002?
Alligator is the most versatile choice: it offers water resistance, regular grain, and lasting elegance. For those who love patina and the passage of time, vegetable-tanned calf leather is ideal. For intensive water use, NATO fabric or FKM rubber ensure total impermeability and zero maintenance.
How do I change the strap on the Seamaster Diver 300M 210.30.42.20.04.002?
The model uses standard spring bars on the 20mm lugs. Using a dedicated tool (spring bar tool), gently press toward the center of the spring to release it from the lug, then remove the used strap. Insert the new strap by aligning it with the lugs and release the spring. If you prefer to avoid manual operations, contact the Casati Milano atelier for professional strap replacement.
Can I use an aftermarket strap compatible with the Seamaster Diver 300M 210.30.42.20.04.002?
Yes, any strap with a 20mm lug width is compatible. We recommend verifying the exact width before purchase by contacting the supplier. The artisanal straps from milanostraps.it are specifically tested for the 210.30.42.20.04.002 and are shipped ready to use.
How long does a natural leather strap last on a Seamaster Diver 300M?
The lifespan depends on the material (alligator, calf, shell cordovan) and exposure to fresh water. A vegetable-tanned alligator strap typically lasts 3-5 years of daily use before requiring replacement or restoration. Frequent exposure to fresh water reduces durability; the Casati Milano atelier guarantees 18 months on its bespoke straps, with the option to renew.
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

