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Casio G-SHOCK GM-B2100D-1AER Solar Bluetooth Bracelet Watch - W17648
Ref. GM-B2100D-1AER
Sits in Casio’s upper tier here — more premium than three quarters of the Casio watches we list, which start at £25.
Price range £25 to £919 across 136 Casio watches in stock.The GM-B2100D is the first full-metal member of the 2100 family, a line that traces its shape directly back to the DW-5000C of 1983 — the original G-SHOCK. The octagonal bezel and dimpled bracelet links are both lifted from that first model, but here rendered entirely in stainless steel rather than resin, giving the watch a solidity and presence that earlier 2100s, for all their appeal, could not quite claim. The screw-back case is part of that same logic: protection built in at every seam. At 12.8mm thick for a watch rated to 200m, it sits considerably flatter than the rating might suggest, and the full-metal construction that accounts for most of its 165g keeps it planted rather than restless on the wrist. The analogue hands shift clear of the digital display on demand, which is a small but genuinely useful piece of engineering on a dial carrying this much information. Bluetooth pairing keeps the time correct without any manual intervention, and the solar cell means the battery question is largely academic — seven months from a full charge with no light at all, and effectively indefinite with any regular exposure.
- Reference
- GM-B2100D-1AER
- Brand
- Casio
- Collection
- G-Shock
- Case size
- 44mm
- Case material
- Stainless steel
- Case shape
- Octagonal
- Dial
- Black
- Crystal
- Mineral
- Movement
- Solar
- Functions
- Date
- Water resistance
- 200m
- Bracelet / strap
- Stainless steel bracelet
- Strap colour
- Silver
- Clasp
- Three-fold clasp
- Lume
- Luminous
- Retailer
- Goldsmiths
Additional specifications
- Weight
- 165g
Learn more about Casio
Tadao Kashio founded Kashio Seisakujo in Tokyo in 1946 as a machine shop. The company's first success was a finger ring that held a cigarette, and its second was the 14-A of 1957 — the world's first all-electric compact calculator, which used solenoids rather than gears.
Casio entered watchmaking in 1974 with the Casiotron, a digital watch with an automatic calendar that knew the varying lengths of months. The company approached watches as an electronics manufacturer rather than a horological one, and that difference produced the G-Shock.
The G-Shock came from a single engineer, Kikuo Ibe, who broke a watch his father had given him and set out to build one that could not break. The specification was three tens: survive a ten-metre drop, ten bars of water pressure, and ten years of battery life. It took over two hundred prototypes, and the solution was suspending the module inside the case on a cushioned internal structure rather than mounting it rigidly. The DW-5000C shipped in 1983.
It became one of the most durable product designs in any category, adopted by militaries, emergency services, and skateboarders alike, and Casio has since added solar charging, radio and GPS timekeeping, Bluetooth, and full-metal and carbon variants.
Casio also produces the Edifice, Pro Trek, and Oceanus lines, and remains an independent Japanese public company.
- 1946
- Tadao Kashio founds the company in Tokyo.
- 1974
- The Casiotron is Casio's first digital watch.
- 1983
- The G-Shock DW-5000C survives Kikuo Ibe's three-tens brief.
- 1994
- The Frogman extends G-Shock to ISO dive certification.
Also in 7 collections
This watch appears in the Casio G-Shock range (84), Back in Stock (4,683), Stainless Steel Watches (3,109), Watches 44mm and Over (827), Sports Watches (800), Dive Watches (568) and Solar & Kinetic Watches (208).
Manufacturer’s guarantee
What the specifications mean
A watch built to be worn hard and got wet.
Strengths
- 200m water resistance, rated for actual diving
- Luminous hands and markers for low light
- One of Casio's more premium watches
Worth knowing
- 44mm sits at the larger end
Casio G-SHOCK GM-B2100D-1AER Solar Bluetooth alternatives
Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.
| Specification | GM-B2100D-1AER | CB5894-50E | SNE595P1 |
|---|---|---|---|
| Price | £499 | £549 | £500 |
| Case size | 44mm | 43mm | 41mm |
| Water resistance | 200m | 200m | 200m |
| Movement | Solar | Solar | Solar |
| 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 200m it is rated for swimming, snorkelling and recreational 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 comparedIs it a men's or women's watch?
Listed as men's.
Cheapest place to buy
Goldsmiths is the only UK retailer we track stocking this reference, so there is nothing to compare it against today.
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