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Citizen BM7637-81H Weekender Grey IP Bracelet Watch - W38386
Ref. BM7637-81H
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Part of Citizen's Odyn collection, this watch is built around a single idea: a fully monochromatic sport watch that asks nothing of its owner in terms of upkeep. The E111 Eco-Drive calibre charges from any light source and will run for six months in complete darkness, which in practice means the watch simply never stops. That movement is Japanese-made and sits behind Citizen's broader Eco-Drive philosophy — no battery changes, no disposal, no interruption. At 41mm across and only 9.7mm deep, it wears flatter than the case width suggests, and the 48mm lug-to-lug span keeps it from dominating smaller wrists. The integrated H-link bracelet flows directly from the case in the manner of sport watches costing considerably more, and the grey ion-plating ties case, bracelet and dial into one unbroken tone. The waffle-textured dial gives the grey surface enough depth to read well in flat light, where an unbroken smooth dial would simply disappear.
- Reference
- BM7637-81H
- Brand
- Citizen
- Collection
- Odyn
- Case size
- 41mm
- Case thickness
- 9.7mm
- Lug width
- 22mm
- Case material
- Black PVD
- Case shape
- Octagonal
- Dial
- Grey
- Crystal
- Mineral
- Movement
- Solar
- Calibre
- E111
- Functions
- Date
- Water resistance
- 100m
- Bracelet / strap
- Stainless steel bracelet
- Strap colour
- Grey
- Clasp
- Deployant clasp
- Lume
- Luminous
- Retailer
- F.Hinds
Additional specifications
- Lug-to-lug
- 48mm
Learn more about Citizen
The Shokosha Watch Research Institute began in Tokyo in 1918, and the Citizen name was given to its first pocket watch in 1924 by the then mayor of Tokyo, Shinpei Goto, who wanted a watch that would be available to ordinary citizens rather than only the wealthy. The company formally took the name in 1930.
That founding intention has held. Citizen is the largest watch manufacturer in the world by volume and is fully vertically integrated, making its own movements, cases, and electronic components.
Its most significant technology is Eco-Drive, introduced in 1976 and refined over decades. A photovoltaic cell beneath the dial converts any light — including indoor light — into stored energy, so the watch never needs a battery change. Citizen has sold well over a hundred million Eco-Drive watches, and the environmental argument is substantial: hundreds of millions of cells not discarded.
The company also produced the first analogue quartz watch with a titanium case in 1970, the first professional dive watch with an electronic depth sensor, and the Caliber 0100, an Eco-Drive movement accurate to within one second a year — the most accurate independent watch movement ever put into production.
Citizen owns Bulova, Frederique Constant, Alpina, and the movement manufacturer Miyota, whose calibres power a large share of the affordable mechanical watch market worldwide.
- 1918
- The Shokosha Watch Research Institute is founded.
- 1924
- The Citizen name is given to its first pocket watch.
- 1976
- Eco-Drive light-powered technology is introduced.
- 2018
- The Caliber 0100 achieves accuracy of one second a year.
Also in 4 collections
This watch appears in Back in Stock (3,635), Stainless Steel Watches (3,604), Grey Dial Watches (284) and Solar & Kinetic Watches (263).
Manufacturer’s guarantee
What the specifications mean
Strengths
- 100m water resistance covers swimming and watersports
- 48mm lug-to-lug keeps the 41mm case wearable
- Luminous hands and markers for low light
Citizen BM7637-81H Weekender Grey IP alternatives
Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.
| Specification | BM7637-81H | SSC771P1 | R8873624008 |
|---|---|---|---|
| Price | £269 | £299 | £259 |
| Case size | 41mm | 41mm | 42mm |
| Water resistance | 100m | 100m | 100m |
| Movement | Solar | Solar | Solar |
| Strap | Stainless steel bracelet | Stainless steel bracelet | Mesh bracelet |
| This watch | Closely matched | 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 can, over time. Mineral glass handles daily wear but will pick up fine scratches that sapphire would not.
Sapphire, mineral and acrylic comparedDoes it need a battery?
No. It charges from light, and the cell behind that is designed to last a decade or more.
Quartz, automatic and solar comparedWhat size strap does it take?
22mm. 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 48mm, which suits wrists from roughly 16.5cm (6½ 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.
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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