Seiko has added two new models to its Seiko 5 GMT collection which will be shipping soon – the SSK023K1 and SSK025K1. These watches continue Seiko's tradition of offering feature-packed and affordable timepieces, and follows the success of the “5KX GMT” models that were released just 2 years ago. These upcoming tool watch GMTs aim to go side by side with the dive watch GMTs to offer Seiko fans and the more general watch community more choices.

Seiko's Seiko 5 Sports collection is a range of rugged and versatile watches that combine reliability, functionality, and value. In 2022, the brand introduced a trio of Seiko 5 GMT models housed in the classic SKX-style case, which were widely praised for their exceptional value proposition. Now, Seiko has taken a similar approach with the new SSK023K1 and SSK025K1, but in a sleeker and more versatile field watch form factor.

The Looks

Source: @monochromewatches on IG


The SSK023K1 (Steel) and SSK025K1 (Black) feature a well-proportioned 39.4mm stainless steel case with a thickness of 13.6mm and a lug-to-lug measurement of 47.9mm. The watches are equipped with a domed Hardlex crystal and offer a water resistance rating of 100 meters.

The SSK023K1 comes paired with a five-row brushed stainless steel bracelet that looks particularly good with the case’s sleek lugs. The SSK025K1 on the other hand opts for a black leather NATO strap with matching black-coated steel hardware which does look refined, although it adds some bulk to the watch making it appear thicker than it is.


Source: @seikospain on IG


The dial designs vary slightly between the two models. The SSK023K1 features a classic black dial with white numerals and a reddish-orange seconds and 24-hour hand for contrast. The SSK025K1, on the other hand, incorporates a greenish hue for its numerals and a different color scheme for its 24-hour hand, which is black from the center until just before the tip, where it adopts the familiar orange shade.

Both dials sport a grainy black military-inspired design with Lumibrite-coated indices and numerals, a 24-hour scale, and a date window with an applied frame. This may not be for minimalist watch fans, but for field watch collectors, this has just the right look. While the stainless steel bezel is fixed, it features a polished edge that adds a touch of class to an otherwise rugged looking timepiece.

The Reliable 4R34

Powering these new Seiko 5 Sports models is the same in-house Seiko 4R34 automatic movement that powered the SSK001, SSK003 and SSK005. This reliable caliber offers hacking and hand-winding capabilities, a smooth winding experience, and a respectable power reserve of 41 hours. Timekeeping accuracy is rated at +45 / -35 seconds per day out of the factory, but this can be further regulated to lessen the range.


Source: @horoulogy on IG


One of the standout features of these watches is their GMT functionality. The 4R34 movement allows for an independently adjustable 24-hour hand, enabling the wearer to track a second time zone with ease. This feature, combined with the 24-hour markings on the dial, makes the SSK023K1 and SSK025K1 ideal companions for frequent travelers or those with a global lifestyle. What’s amazing is how Seiko was able to add this functionality while virtually keeping the same dimensions as the 4R35.

How Good Are They?

Source: @seikospain on IG


Priced at a very reasonable $435 (may change depending on when you’re reading this), the Seiko SSK023K1 and SSK025K1 offer an attractive selling point in the realm of affordable GMT watches. While there are other budget-friendly options on the market, few can match the combination of features, quality, and brand heritage that Seiko brings to the table at this price range.

For budding watch enthusiasts or those seeking their first mechanical timepiece, these Seiko 5 Sports models could be the perfect entry point. Their versatile design, robust construction, and GMT functionality make them suitable for everyday wear, while their affordable pricing ensures that they won't break the bank.

Will it be as popular as its predecessors though? Time will tell.



The Seiko SSK023K1 and SSK025K1 are impressive additions to the brand's Seiko 5 Sports collection, offering a compelling blend of functionality, design, and value. With their GMT capabilities, robust automatic movements, and versatile field watch aesthetics, these timepieces are poised to become favorites among enthusiasts seeking an affordable and capable travel companion.

You must be wondering right now if you can mod this upcoming Seiko release. It’s easy to assume that parts for the NH34 will be plug and play with this watch, but until the modfam takes a crack at these GMT tool watches, it is hard to say. While you’re waiting for the answers whether the SSK023/025 are mod-friendly though, you can modify your SSK dive watches in the meantime with new bezels, inserts, crystals, and hands from our ever-expanding catalog. You can also build your GMT watch from scratch with our cases that are natively compatible with the NH34 movement.

Happy modding!

April 07, 2024 — Jeremiah A

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