Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsSeiko’s official listings confirm two new 5 Sports Field GMT references: HDB001 and HDB002. The UK store names them Khaki Drill and Desert Sand, respectively. Seiko’s detailed product specifications retrieved for this pair are for HDB001 only, so the available information does not establish that color is their sole difference—or a formal global launch date.
What are the Seiko HDB001 and HDB002?
They are Seiko 5 Sports Field GMT references listed in Seiko’s official Japan collection and UK online store. The UK listings identify the products as HDB001K1 and HDB002K1; the Japan collection uses the HDB001J and HDB002J suffixes. Those are market-specific reference codes, not evidence of different core models.
Seiko UK describes the Field collection as drawing on the military “trench watch” style, originally intended to be robust and reliable in difficult conditions. The collection page also lists SSK023K1 as another mechanical GMT in the Field range, but the available details here are not enough for a full specification comparison.
HDB001 vs HDB002: confirmed differences
| Reference | Official UK color name | UK price when accessed (2026-10-07) | Japan listed reference and price when accessed (2026-10-07) |
|---|---|---|---|
| HDB001 | Khaki Drill | £410 | HDB001J — ¥64,900 |
| HDB002 | Desert Sand | £410 | HDB002J — ¥64,900 |
These are prices shown by Seiko’s official UK store and Japan collection at the time accessed, not universal prices; listings and prices can change. The official material confirms the different color names and matching listed prices in those markets. It does not confirm that color is the only difference between the watches.
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#1 Best Overall
- 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
HDB001 specifications confirmed by Seiko
Seiko Watch Corporation’s undated HDB001 product specification gives the following figures and functions. These details apply specifically to HDB001; a corresponding detailed HDB002 product specification was not confirmed in the official material available here.
- Movement: Caliber 4R34, automatic with manual winding.
- Power reserve: Approximately 41 hours.
- Jewels: 24.
- Functions: 24-hour hand/dual-time function and date.
- Case dimensions: 39.4 mm diameter, 13.6 mm thickness and 47.9 mm lug-to-lug.
- Crystal: Curved Hardlex.
- Lug distance: 20 mm.
- Water resistance: 10 bar.
Does “covert release” mean Seiko quietly launched them?
The official listings establish that the HDB001 and HDB002 are present in Seiko’s Japan collection and UK store. The available official sources do not establish a formal global announcement date or explain why the release is described as “covert.” That wording should be treated as a characterization, not a documented Seiko launch strategy.
Rank #2
- 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
Where do the HDB001 and HDB002 sit in the Field collection?
They join a Seiko 5 Sports Field range that Seiko UK frames around trench-watch styling. The UK collection page also lists SSK023K1 as a mechanical GMT, but that confirmation alone does not support comparing its dimensions, movement details or other specifications with the HDB references.
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