All Seiko lines › Other Seiko ranges › Movement type not published
Seiko, 42.4 mm (4R37)
4 versions of this watch are on Seiko's own sites right now, across 3 regions. Last checked Nov 13, 2026.
Estimated US price: About $345 to $375, converted from Seiko's list price in THB.
Retailers ask: no retailer listing matched yet.
Photos are Seiko's own, shown from Seiko's sites. Click a photo to jump to that version.
- Calibre
- 4R37
- Case diameter
- 42.4 mm
- Thickness
- 14.5 mm
- Lug to lug
- Not published
- Variants listed now
- 4
- Regions
- 3
Listed means the watch was on an official Seiko regional site or store at the last check. It does not mean it is in stock, and it does not tell us whether Seiko is still making it.
Versions listed now
Same case and movement in every row. What changes is the colour, the strap or bracelet, the finish and where Seiko sells it. Seiko's spec sheets don't state dial colour, so a colour appears only where Seiko's US store tags one.
| Photo | Reference | Colour | Strap / bracelet | Case | Edition | Listed in | Seiko list price | Buy |
|---|---|---|---|---|---|---|---|---|
 | SSA381 Also coded SSA381K1 | Not published | Not stated | Stainless steel Translated from Seiko's regional page | Regular | 3 regions Brazil, Indonesia, Thailand | 11,600 THB Thailand · Nov 13, 2026 about $345 in US dollars | No seller matched yet |
Where Seiko lists it (3 sites) and its list pricesBuying options (0)No seller offer has been matched to this exact variant yet. | ||||||||
 | SSA383 Also coded SSA383K1 | Not published | Nylon Seiko's regional wording | Stainless steel (hard coating) Translated from Seiko's regional page | Regular | 3 regions Brazil, Indonesia, Thailand | 12,000 THB Thailand · Nov 13, 2026 about $355 in US dollars | No seller matched yet |
Where Seiko lists it (3 sites) and its list pricesBuying options (0)No seller offer has been matched to this exact variant yet. | ||||||||
 | SSA391 Also coded SSA391K1 | Not published | Cow leather Translated from Seiko's regional page 91 g | Stainless steel Translated from Seiko's regional page | Regular | 3 regions Brazil, Indonesia, Thailand | 11,600 THB Thailand · Nov 13, 2026 about $345 in US dollars | No seller matched yet |
Where Seiko lists it (3 sites) and its list pricesBuying options (0)No seller offer has been matched to this exact variant yet. | ||||||||
 | SSA389 Also coded SSA389K1 | Not published | Not stated | Stainless steel (hard coating) Translated from Seiko's regional page | Regular | 2 regions Brazil, Thailand | 12,700 THB Thailand · Nov 13, 2026 about $375 in US dollars | No seller matched yet |
Where Seiko lists it (2 sites) and its list pricesBuying options (0)No seller offer has been matched to this exact variant yet. | ||||||||
Where to buy
No retailer listing has been matched to a version on this line yet.
Estimated US prices use Seiko's US list price where there is one. Otherwise they are the middle of Seiko's list prices in other countries, converted at rates dated Nov 12, 2026 from ExchangeRate-API (free open endpoint). Those list prices include each country's sales tax, so a converted figure usually runs higher than a US price would. Retailer prices are asking prices on the date shown, not sold prices, and leave out shipping, tax and import charges.
The build
| Movement | Automático com capacidade de corda manual | Seiko product page |
|---|---|---|
| Functions | Ponteiro indicador de 24 horas Função de parada do segundo ponteiro | Seiko product page |
| Power reserve / battery | Aprox. 41 horas | Seiko product page |
| Water resistance | 10 ATM | Seiko product page |
| Crystal | Hardlex curvo | Seiko product page |
| Lug width | 21 mm | Seiko product page |
| Seiko case codes | 4R37-01H0 | Seiko catalog data |
Why these share a page
Every version here is published by Seiko with calibre 4R37 and either the same Seiko case code or the same case size. 8 reference codes lead to this page.
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