Seiko · Prospex Divers

Strap for Seiko Prospex Divers SPB301

The Prospex Diver 1970 Save the Ocean takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

  • 4.8 out of 5 · 269 reviews
  • Ships in 1–3 working days
  • Worldwide shipping
  • 30-day returns
  • 12-month warranty on manufacturing defects
  • Hand-stitched in Milan
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Lug width20 mm
Case diameter43 mm
ReferenceSPB301
FamilyProspex Divers
MovementSeiko caliber 6R35 Hours, Minutes, Seconds | Date
Year2022
CaseStainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Standard spring bar · length 20 mm · Ø 1.8 mm double flange

Prospex Diver 1970 Save the Ocean — watch

Your watch with our straps

Prospex Divers SPB301 with Grand Cavalier Leather Strap Orange
Prospex Divers SPB301 with Vintage Brown Calfskin Strap — Natural Patina
Prospex Divers SPB301 with Brown Italian Leather Strap

Calf, Orange

Grand Cavalier Leather Strap Orange

€120

★ 4.9 · 12

1 / 109

Real photos of the strap and the case. No generated images.

What length do I need?

Measure your wrist with a tailor's tape or a piece of string, comfortably snug.

Wrist circumferenceLength (long side / short side)
15.0–16.4 cm110 / 70 mm
16.5–17.8 cm115 / 75 mm
17.9–19.0 cm120 / 80 mm
19.1–20.4 cm125 / 80 mm
20.5–21.6 cm130 / 85 mm
21.7–22.9 cm135 / 85 mm
over 22.9 cmon request

The ready-to-wear strap is 115 × 75 mm. For a smaller or larger wrist I make it in the right length: order your length.

What I'm asked about the Seiko Prospex Divers SPB301

What strap size does the Seiko Prospex Divers SPB301 take?

The Seiko Prospex Divers SPB301 needs 20 mm between the lugs. It's the size I've been fitting on it for years.

Can the strap on the Seiko Prospex Divers SPB301 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 Seiko Prospex Divers SPB301?

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 43 mm diver I go for a full-thickness strap, not a thin one.

Which strap do you recommend for the Seiko Prospex Divers SPB301?

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 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

Updated on · by Antonio Zichichi