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Seiko SMGG21P1 Digital Quartz Bracelet Watch - W25547
Ref. SMGG21P1
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The Rotocall name traces back to a 1982 Seiko digital that NASA astronauts wore on space missions, chosen specifically because the outer bezel could be operated with gloved hands. That bezel is the watch's defining mechanism: spinning it cycles through chronograph, dual time, alarm and countdown modes without sub-menus or recessed pushers, just a direct mechanical click between functions. The SMGG21P1 is a faithful recreation of that original, released in late 2025, down to the octagonal bezel insert in alternating blue and grey blocks and the orange text on the grey digital display. At 37mm across and 10.6mm thick it sits flush and unobtrusive, closer to what a dress watch does on the wrist than most digitals manage. The five-row bracelet mixes brushed and polished links, and at 107 grams the whole thing has enough substance to feel considered without becoming a burden through the day. The clasp releases on both sides, which matters more than it sounds after a year of daily use.
- Reference
- SMGG21P1
- Brand
- Seiko
- Collection
- Rotocall
- Case size
- 37mm
- Case thickness
- 10.6mm
- Lug width
- 20mm
- Case material
- Stainless steel
- Case shape
- Octagonal
- Dial
- Grey
- Crystal
- Hardlex
- Bezel
- Bidirectional rotating
- Movement
- Quartz
- Calibre
- A824
- Functions
- Chronograph, GMT
- Water resistance
- 100m
- Bracelet / strap
- Stainless steel bracelet
- Strap colour
- Silver
- Clasp
- Three-fold clasp
- Lume
- Luminous
- Retailer
- F.Hinds
Additional specifications
- Lug-to-lug
- 43.5mm
Learn more about Seiko
Kintaro Hattori opened a watch and clock shop in Tokyo in 1881, aged twenty-one, and began manufacturing under the name Seikosha — roughly, house of exquisite workmanship — in 1892. The Seiko name appeared on watches from 1924.
The company's significance is that it broke the Swiss monopoly twice. First on precision: Seiko was appointed official timekeeper of the 1964 Tokyo Olympics and built the quartz chronometers and printing timers to do it, and in the 1960s its movements placed highly at the Neuchâtel and Geneva observatory trials against the best Swiss houses.
Then on technology. On Christmas Day 1969 Seiko released the Astron, the world's first quartz wristwatch, accurate to five seconds a month where mechanical watches managed that per day. The consequences for Switzerland were catastrophic — employment in the Swiss industry fell by roughly two-thirds over the following decade. Seiko deliberately did not enforce its quartz patents, allowing the technology to spread.
The same year it produced the 6139, among the first automatic chronographs, and it has since introduced Kinetic, Spring Drive — a hybrid regulating a mechanical mainspring electronically, giving a perfectly gliding seconds hand — and its own dive and field lines.
Seiko remains fully vertically integrated, making its own hairsprings, quartz crystals, and even the Zaratsu-polished cases, at price points from under a hundred pounds upward.
- 1881
- Kintaro Hattori opens his Tokyo shop.
- 1924
- The first watches carry the Seiko name.
- 1964
- Official timekeeper of the Tokyo Olympics.
- 1969
- The Astron becomes the first quartz wristwatch.
- 1999
- Spring Drive enters production.
Also in 4 collections
This watch appears in Stainless Steel Watches (3,600), Chronograph Watches (1,400), Grey Dial Watches (283) and GMT Watches (278).
Manufacturer’s guarantee
What the specifications mean
Strengths
- 100m water resistance covers swimming and watersports
- 37mm suits most wrists
- 43.5mm lug-to-lug keeps the 37mm case wearable
- Luminous hands and markers for low light
- Second time zone for travelling
Seiko SMGG21P1 Digital alternatives
Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.
| Specification | SMGG21P1 | T1019101135100 | VV335BKGD |
|---|---|---|---|
| Price | £336 | £355 | £325 |
| Case size | 37mm | 36mm | 37mm |
| Water resistance | 100m | 100m | 50m |
| Movement | Quartz | Quartz | Quartz |
| Strap | Stainless steel bracelet | Stainless steel bracelet | Stainless steel bracelet |
| This watch | Closely matched |
|
Your new watch
Frequently asked questions, and things you should know about this watch
Can I swim with it?
Yes. At 100m it is rated for swimming and snorkelling, though not for diving.
Water resistance explainedWill the glass scratch?
It resists most everyday knocks. Hardlex is a hardened mineral glass — tougher than standard mineral, softer than sapphire.
Sapphire, mineral and acrylic comparedDoes it need a battery?
Yes. It is quartz, so expect a battery change every two to three years at a jeweller.
Quartz, automatic and solar comparedWhat size strap does it take?
20mm. Any strap of that width will fit, and on most modern watches quick-release bars make the swap a two-minute job with no tools.
Will it fit my wrist?
Lug-to-lug is 43.5mm, which suits wrists from roughly 15cm (6 inches) upward.
Lug-to-lug decides fit more than case diameter does.
How to size a watch to your wristIs it a men's or women's watch?
Listed as men's, though at 37mm it sits in the range that suits anyone.
Cheapest place to buy
F.Hinds is the only UK retailer we track stocking this reference, so there is nothing to compare it against today.
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