Omega · Seamaster Diver 300M
Strap for Seamaster Diver 300M Master Co-Axial 42 Stainless Steel / Green / Bracelet
Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
Recommended spring bar
Straps for the Seamaster Diver 300M 210.30.42.20.10.001
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 Diver 300M 210.30.42.20.10.001, seen from the bench
Frequently asked questions
What is the lug width of the Omega Seamaster Diver 300M 210.30.42.20.10.001?
The lug width of this model is 20mm. This measurement should be verified using a digital caliper positioned between the inner lugs of the case, and is essential for ordering a compatible strap.
Which strap is best suited for the Seamaster Diver 300M 210.30.42.20.10.001?
For elegant daily wear: wide grain alligator in navy blue or grey. For water durability: vulcanized rubber or NATO. For natural ageing: vegetable-tanned calf in brown or black. The choice depends on primary use and personal aesthetic preference.
How do you change the strap on the 210.30.42.20.10.001?
This model features an integrated deployant clasp on the case. You must unlock the deployant mechanism (usually via a side button), remove the original strap, insert the new strap with a straight end terminal compatible with the deployant, and close it until the safety click.
Can I fit an aftermarket compatible strap on this Seamaster Diver?
Yes, provided the strap is certified 20mm and equipped with a straight end terminal compatible with the original case deployant. Milanostraps offers handcrafted 20mm leather straps customizable in leather, sizes and stitching, guaranteed for 18 months.
How long does a leather strap last on a diving watch like the 210.30.42.20.10.001?
A quality leather strap (alligator or vegetable-tanned calf) lasts 3-5 years under moderate use conditions. On a 300M diver frequently exposed to salt water, the lifespan reduces to 2-3 years. Vulcanized rubber is more resistant to moisture and offers a lifespan of 5-7 years.
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