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Seiko’s 2022 Prospex brochure groups three Sumo diver references together: SPB321J1, SPB323J1 and SPB325J1. They share the same listed core specifications, including an automatic 6R35 movement, a 45.0 mm case and a 200 m diver rating. The clearest documented configuration difference is the strap: the first two are shown on coated stainless-steel bracelets, while the SPB325J1 is shown with a silicone strap.
Which watches make up the 2022 Sumo trio?
The references are SPB321J1, SPB323J1 and SPB325J1, as listed together in Seiko’s 2022 Prospex brochure. The brochure supports comparing their reference numbers and strap configurations, but its accessible text does not establish a dial-color distinction or other styling differences between them.
How do the three references compare?
| Reference | Configuration shown in Seiko’s 2022 brochure | Movement | Case diameter | Diver rating |
|---|---|---|---|---|
| SPB321J1 | Stainless-steel case with super-hard coating; coated stainless-steel bracelet | Automatic 6R35 | 45.0 mm | 200 m diver |
| SPB323J1 | Stainless-steel case with super-hard coating; coated stainless-steel bracelet | Automatic 6R35 | 45.0 mm | 200 m diver |
| SPB325J1 | Stainless-steel case with super-hard coating; silicone strap | Automatic 6R35 | 45.0 mm | 200 m diver |
These specifications and configurations are manufacturer-listed in the 2022 brochure; they should not be read as a statement about current regional availability or present-day listings.
What specifications do they share?
Seiko lists the same core case and diver features for all three references:
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#1 Best Overall
- SEIKO WATCH – Seiko SFK001 wristwatch with a GMT hand function.
- DIAL DESIGN – Blue dial provides the watch face design.
- CRYSTAL – Sapphire crystal construction.
- BEZEL – Unidirectional rotating bezel design.
- WATCH DIAMETER – 45 mm.
- Sapphire crystal with anti-reflective coating on the inner surface.
- Unidirectional rotating bezel.
- Screw case back and screw-down crown.
- Automatic 6R35 movement.
- 45.0 mm case diameter and a 200 m diver rating.
The brochure identifies the cases as stainless steel with super-hard coating. Its strap descriptions distinguish the two bracelet versions from the silicone-strap SPB325J1.
How should you choose between them?
On the specifications established in the brochure, the practical choice is between the two references pictured with coated stainless-steel bracelets and the SPB325J1 pictured with a silicone strap. The brochure does not substantiate a further difference in dial color or other styling, so confirm any such detail against the specific product listing or Seiko documentation before choosing on that basis.
Quick Recap
Best Value
- STAINLESS STEEL CASE built to endure with style, making this watch your perfect daily companion
- AUTOMATIC MOVEMENT for seamless precision in every tick of this watch
- SCRATCH-RESISTANT CRYSTAL to maintain a pristine look even with daily wear and tear on your watch
- LUMINESCENT HANDS for effortless readability in low-light conditions, ensuring you never miss a moment with this watch
- WATER RESISTANT DESIGN ensuring your watch is ready for any adventure, rain or shine
Rank #4
- AUTOMATIC MOVEMENT: Seiko 4R35 automatic movement includes manual winding, 23 jewels, date display, stop-second function, and approximately 41 hours of power reserve.
- 200M DIVER'S WATER RESISTANCE: Rated to 200 meters / 660 feet for diving, with a screw-down crown and screw case back.
- STAINLESS-STEEL CASE: 41.7mm stainless-steel case measures 12.3mm thick with a 49.5mm lug-to-lug distance and 20mm lug width.
- HARDLEX CRYSTAL: Durable Hardlex crystal protects the dial, while LumiBrite on the hands, indexes, and bezel improves low-light visibility.
- DIVER-READY DESIGN: Unidirectional rotating bezel and three-fold clasp with secure lock, push-button release, and extender provide practical functionality.
Rank #3
- STAINLESS STEEL CASE built to endure with style, making this watch your perfect daily companion
- AUTOMATIC MOVEMENT for seamless precision in every tick of this watch
- SCRATCH-RESISTANT CRYSTAL to maintain a pristine look even with daily wear and tear on your watch
- LUMINESCENT HANDS for effortless readability in low-light conditions, ensuring you never miss a moment with this watch
- WATER RESISTANT DESIGN ensuring your watch is ready for any adventure, rain or shine
Rank #2
- Automatic winding type with manual winding mechanism
- Cal. 6R35 Movement, 24 Jewels, Made in Japan
- Power reserve: approximately 70 hours
- Second-hand-halt mechanism (Hacking)
- 120 clicks Unidirectional Bezel
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
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