Omega · Seamaster Diver 300M
Strap for Omega Seamaster Diver 300M 210.30.42.20.01.018
The Seamaster Diver 300M Master Co-Axial 42 No-Date Stainless Steel / Black - Orange / Mesh 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 210.30.42.20.01.018
Selected for the 20 mm lug width · workshop selection
Blue Alligator and Rubber Hybrid Strap · rubber, for the water€138
Green Rubberized Alligator Strap with Ecru Tribal Stitching · rubber, for the water€149
Black Alligator Strap with Light Blue Edges€149
Red Alligator Strap Water Resistant€195
Military Alligator Green Strap★ 5 · 1€138
Hammered Calfskin Strap Light Blue€98
What I'm asked about the Omega Seamaster Diver 300M 210.30.42.20.01.018
What strap size does the Omega Seamaster Diver 300M 210.30.42.20.01.018 take?
The Omega Seamaster Diver 300M 210.30.42.20.01.018 needs 20 mm between the lugs, usually 16 mm at the buckle. It's the size I've been fitting on it for years.
Can the strap on the Omega Seamaster Diver 300M 210.30.42.20.01.018 be changed?
Yes. It has spring bars between the lugs: with the right tool the strap comes off in a minute. If you'd rather not risk a scratch, I do it in the workshop.
Can I put a leather strap on the Omega Seamaster Diver 300M 210.30.42.20.01.018?
Yes, in 20 mm leather, as long as you don't wear it in the water: leather doesn't like the sea or the pool. For days in the water, rubber. On a 42 mm diver I go for a full-thickness strap, not a thin one.
Which strap do you recommend for the Omega Seamaster Diver 300M 210.30.42.20.01.018?
Rubber if you wear it in the water; otherwise a 20 mm calf strap, full thickness. You'll find it ready in the 20 mm collection. If you'd rather have something built on your wrist, the Casati atelier.
The Seamaster Diver 300M 210.30.42.20.01.018, seen from the bench
Frequently asked questions
What is the best strap for the Seamaster Diver 300M 210.30.42.20.01.018?
It depends on usage: vegetable-tanned alligator offers hybrid elegance, ideal for the office and weekends. For frequent diving use, an FKM rubber or medical-grade silicone strap is waterproof and slip-resistant. A calf with natural patina develops character over time, while a ballistic nylon NATO guarantees versatility and quick changes.
Is an aftermarket strap compatible with the Seamaster Diver 300M 210.30.42.20.01.018?
Yes, any strap with a 20mm lug width is compatible. Always verify that the strap is exactly 20mm, not approximations. Artisanal leather straps, technical rubber, or superior-quality fabric do not damage the case and offer aesthetic freedom compared to the original bracelet.
How long does a leather strap last for my Seamaster?
A quality leather strap (alligator, calf, shell cordovan) lasts 3–5 years with regular use and proper maintenance. Prolonged exposure to salt water reduces durability. An FKM rubber strap resists 5–10 years if washed regularly with fresh water. Casati Milano offers an 18-month warranty on artisanal straps and recommends annual inspection for early replacement if necessary.
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
The atelier's website: casatimilano.com