Seiko HBB001
Ref. HBB001 · In production
- Case41.7 mm
- Thick12.3 mm
- Lug-to-lug49.5 mm
- Water res.200 m
- MovementAutomatic
- CrystalHardlex (mineral)
Overview
The Seiko HBB001 is a diver watch from the Prospex collection, part of the Sea family. It has a 41.7 mm stainless steel case, 12.3 mm thick, 49.5 mm from lug to lug. Inside is a automatic movement (calibre 4R35) with 41 h of power reserve. You also get 200 m water resistance, a hardlex (mineral) crystal and a bracelet.
Who it suits
- Wrists of roughly 16.7–18.6 cm (6.6–7.3 in), by our Watch Finder sizing guide
- Swimming, snorkelling and diving
Strengths
- Certified to the ISO 6425 diver's standard (200 m)
- Screw-down crown helps keep water out
- Hacks and hand-winds, so it is easy to set
Trade-offs
- Hardlex (mineral) crystal scratches more easily than sapphire
- 41 h power reserve: it stops after about a day and a half off the wrist
Written by Watch.co from the published specs below. These are not owner reviews.
Full specifications
Case
| Case diameter | 41.7 mm | seikowatches.com · 23 Oct 2026 |
|---|---|---|
| Thickness | 12.3 mm | seikowatches.com · 23 Oct 2026 |
| Lug-to-lug | 49.5 mm | seikowatches.com · 23 Oct 2026 |
| Case material | Stainless steel | seikowatches.com · 23 Oct 2026 |
| Crystal | Hardlex (mineral) | seikowatches.com · 23 Oct 2026 |
| Caseback | Screw | seikowatches.com · 23 Oct 2026 |
| Bezel | Unidirectional rotating | seikowatches.com · 23 Oct 2026 |
| Water resistance | 200 m | seikowatches.com · 23 Oct 2026 |
| Screw-down crown | Yes | seikowatches.com · 23 Oct 2026 |
| ISO 6425 diver | Yes | seikowatches.com · 23 Oct 2026 |
| Magnetic resistance | 4,800 A/m | seikowatches.com · 23 Oct 2026 |
| Weight | 170 g | seikowatches.com · 23 Oct 2026 |
Dial
| Luminous material | LumiBrite | seikowatches.com · 23 Oct 2026 |
|---|---|---|
| Date | Date | our classification |
Movement
| Movement type | Automatic | seikowatches.com · 23 Oct 2026 |
|---|---|---|
| Calibre | 4R35 | seikowatches.com · 23 Oct 2026 |
| Made in-house | Yes | seikowatches.com · 23 Oct 2026 |
| Power reserve | 41 h | seikowatches.com · 23 Oct 2026 |
| Hacking seconds | Yes | seikowatches.com · 23 Oct 2026 |
| Hand-winding | Yes | seikowatches.com · 23 Oct 2026 |
Strap / Bracelet
| Bracelet / strap | Bracelet | seikowatches.com · 23 Oct 2026 |
|---|---|---|
| Lug width | 20 mm | seikowatches.com · 23 Oct 2026 |
Other
| US list price (MSRP) | $595 | seikowatches.com · 23 Oct 2026 |
|---|---|---|
| Production status | In production | seikowatches.com · 23 Oct 2026 |
| Style (our classification) | Diver | our classification |
Specs are summarised in our own words from the brand's product page. Each row links its source and the date we checked it. Fields we haven't verified are left out rather than guessed.
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Questions about the Seiko HBB001
How big is the Seiko HBB001?
The case is 41.7 mm wide, 12.3 mm thick and 49.5 mm from lug to lug.
What movement does the Seiko HBB001 use?
It uses the 4R35 calibre, a automatic movement with 41 h of power reserve.
Can I swim with the Seiko HBB001?
Yes. It is rated to 200 m and certified as an ISO 6425 diver.
Does the Seiko HBB001 have a date?
Yes, it shows the date.
How much is the Seiko HBB001?
The US list price was $595 on seikowatches.com when we checked on 23 Oct 2026. Prices change, so check before you buy.
Will the Seiko HBB001 fit my wrist?
By our sizing guide it sits best on wrists of about 16.7–18.6 cm (6.6–7.3 in). Use the fit checker on this page to test your own wrist.
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