Seiko SRPK01
Ref. SRPK01 · In production
- Case45 mm
- Thick13.2 mm
- Lug-to-lug47.7 mm
- Water res.200 m
- MovementAutomatic
- CrystalSapphire
Seiko SRPK01 size, specs and price at a glance
The Seiko SRPK01 is 45 mm wide and 13.2 mm thick, with a lug-to-lug length of 47.7 mm. It takes 22 mm straps and ships on a bracelet. Inside is the 4R36 automatic calibre, water resistant to 200 m. US list price: $650 when we last checked seikowatches.com (29 Oct 2026).
Strap shopping? See our lug width chart.
Overview
The Seiko SRPK01 is a diver watch from the Prospex collection, part of the Sea family. It has a 45 mm stainless steel case, 13.2 mm thick, 47.7 mm from lug to lug. Inside is an automatic movement (calibre 4R36) with 41 h of power reserve. You also get 200 m water resistance, a sapphire crystal and a bracelet.
Who it suits
- Wrists of roughly 18.1–20.0 cm (7.1–7.9 in), by our Watch Finder sizing guide
- Swimming, snorkelling and diving
Strengths
- Sapphire crystal resists scratches
- 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
- 41 h power reserve: it stops after about a day and a half off the wrist
- Heavy at 198 g
Written by Watch.co from the published specs below. These are not owner reviews.
Full specifications
Case
| Case diameter | 45 mm | seikowatches.com · 29 Oct 2026 |
|---|---|---|
| Thickness | 13.2 mm | seikowatches.com · 29 Oct 2026 |
| Lug-to-lug | 47.7 mm | seikowatches.com · 29 Oct 2026 |
| Case material | Stainless steel | seikowatches.com · 29 Oct 2026 |
| Crystal | Sapphire | seikowatches.com · 29 Oct 2026 |
| Anti-reflective coating | Anti-reflective coating on inner surface | seikowatches.com · 29 Oct 2026 |
| Caseback | Screw | seikowatches.com · 29 Oct 2026 |
| Bezel | Unidirectional rotating | seikowatches.com · 29 Oct 2026 |
| Water resistance | 200 m | seikowatches.com · 29 Oct 2026 |
| Screw-down crown | Yes | seikowatches.com · 29 Oct 2026 |
| ISO 6425 diver | Yes | seikowatches.com · 29 Oct 2026 |
| Weight | 198 g | seikowatches.com · 29 Oct 2026 |
Dial
| Luminous material | LumiBrite | seikowatches.com · 29 Oct 2026 |
|---|---|---|
| Date | Day/Date | our classification |
Movement
| Movement type | Automatic | seikowatches.com · 29 Oct 2026 |
|---|---|---|
| Calibre | 4R36 | seikowatches.com · 29 Oct 2026 |
| Made in-house | Yes | seikowatches.com · 29 Oct 2026 |
| Power reserve | 41 h | seikowatches.com · 29 Oct 2026 |
| Hacking seconds | Yes | seikowatches.com · 29 Oct 2026 |
| Hand-winding | Yes | seikowatches.com · 29 Oct 2026 |
Strap / Bracelet
| Bracelet / strap | Bracelet | seikowatches.com · 29 Oct 2026 |
|---|---|---|
| Lug width | 22 mm | seikowatches.com · 29 Oct 2026 |
Other
| US list price (MSRP) | $650 | seikowatches.com · 29 Oct 2026 |
|---|---|---|
| Production status | In production | seikowatches.com · 29 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.
Variants with the same specs
Same case, movement and bracelet or strap; typically a different dial or finish.
More in Sea
Similar alternatives
Picked with Watch Finder's style tags and sizing.
Comparisons and strap sizing
Questions about the Seiko SRPK01
How big is the Seiko SRPK01?
The case is 45 mm wide, 13.2 mm thick and 47.7 mm from lug to lug.
What movement does the Seiko SRPK01 use?
It uses the 4R36 calibre, a automatic movement with 41 h of power reserve.
Can I swim with the Seiko SRPK01?
Yes. It is rated to 200 m and certified as an ISO 6425 diver.
Does the Seiko SRPK01 have a date?
Yes, it shows the day and date.
How much is the Seiko SRPK01?
The US list price was $650 on seikowatches.com when we checked on 29 Oct 2026. Prices change, so check before you buy.
Will the Seiko SRPK01 fit my wrist?
By our sizing guide it sits best on wrists of about 18.1–20.0 cm (7.1–7.9 in). Use the fit checker on this page to test your own wrist.
Watch.co is independent and not affiliated with any brand. Brand names are used only to identify products.