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The Seiko 5 Sports Field GMT SSK023 and SSK025 share the same 4R34 automatic movement, GMT function and case dimensions. The main choice is the finish and strap: the SSK023 pairs an uncoated stainless-steel case with a steel bracelet, while the SSK025 has a black-coated case and black leather strap. Seiko’s US product pages list them at $450 and $435, respectively; those are reference prices, and stock and pricing can change.
What separates the SSK023 and SSK025?
These are two configurations of Seiko’s 5 Sports Field GMT. The SSK023 has a stainless-steel case and multi-link bracelet. The SSK025 uses a stainless-steel case with black hard coating and a black leather strap. Seiko describes the Field series’ GMT function as a first for the series on both official product pages.
| Specification | SSK023 | SSK025 |
|---|---|---|
| Case and band | Stainless-steel case; multi-link stainless-steel bracelet | Black hard-coated stainless-steel case; black leather strap |
| US listed price | $450, per Seiko’s US product page, accessed 2026 | $435, per Seiko’s US product page, accessed 2026 |
| Listed weight | 147.0 g | 79.0 g |
| Movement | 4R34 automatic with manual winding | 4R34 automatic with manual winding |
| Diameter / thickness / lug-to-lug | 39.4 mm / 13.6 mm / 47.9 mm | 39.4 mm / 13.6 mm / 47.9 mm |
| Crystal | Curved Hardlex | Curved Hardlex |
| Water resistance | 10 bar, per Seiko’s specification | 10 bar, per Seiko’s specification |
| Case back | Not stated on the cited SSK023 product listing | See-through screw case back |
Specifications and prices are from Seiko Watch Corporation’s SSK023 US product page, SSK025 US product page, and their respective SSK023 specifications and SSK025 specifications. Prices are listed US reference prices, not guaranteed checkout totals or evidence of current stock.
How does the GMT function work?
Both models use caliber 4R34 and include a 24-hour hand for dual-time display. The red GMT hand points to the 24-hour scale, allowing the wearer to track another time zone alongside local time. Seiko says the red, five-sided hand is intended to improve legibility against the black dial. The movement also has a date display and stop-seconds function, which stops the seconds hand when setting the time.
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- BLUE DIAL: this handsome men’s watch features a striking deep blue dial with luminous dial indicator hands and markers and date calendar to keep you organized
- BLUE & BLACK BEZEL: with a 24-hour bezel and easy-to-read fourth hand, this GMT watch helps you keep time as you travel
- DURABLE UTILITY: these versatile men’s wrist watches feature a 42.5mm stainless steel watch case and bracelet, for a classic, timeless look.
- WATER-RESISTANT: this rugged sports watch is water-resistant up to 100 meters
- 4R34 CALIBER: equipped with the reliable 4R34 caliber, these automatic watches for men ensure the most accurate in self winding timekeeping, with 41 hours of reserve power and manual winding option
Seiko lists automatic winding with manual winding, 24 jewels and approximately 41 hours of power reserve for each watch. The reserve is the manufacturer’s stated specification, not an independently measured result.
Which model should you choose?
Choose the SSK023 for a steel-bracelet look
The SSK023 is the option to consider if you prefer an uncoated steel case and integrated steel bracelet. Seiko lists its weight at 147.0 g. That is a specification, not a measure of how comfortable it will feel on your wrist; fit and comfort depend on the wearer and cannot be inferred from weight alone.
Choose the SSK025 for a black finish and leather strap
The SSK025 combines a black-coated case with a black leather strap and is listed at 79.0 g. Its lower listed weight should not be treated as a guarantee of greater comfort. It is also the less expensive of the two at Seiko’s US reference prices, by $15, though live pricing may differ.
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- Comes with individual box
- 24 hour hand (dual time display function)
- Day difference + 45 to -35 seconds
- Mechanical automatic movement (with hand winding)
- Lasts approximately 41 hours on maximum winding
What should you know about size and durability?
The listed diameter is 39.4 mm, thickness 13.6 mm and lug-to-lug length 47.9 mm on both models. Each has 20 mm lug spacing, a curved Hardlex crystal, LumiBrite on the hands and indexes, 4,800 A/m magnetic resistance and 10 bar water resistance. These are manufacturer specifications; they do not establish independently tested performance or suitability for every activity.
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The listed 20 mm lug spacing may help when considering replacement straps, but confirm fit and attachment compatibility before buying one. The SSK023 uses a three-fold clasp with secure lock; Seiko lists a see-through screw case back for the SSK025.
Are these newly released watches?
Seiko’s pages identify both as 5 Sports Field GMT models, but do not establish an original announcement date or a current launch schedule. Calling them a new release would therefore imply timing that the available official product information does not confirm.
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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.
