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Casio G-SHOCK GG-B100X-1A3ER Master Of G Mudmaster Green Strap Watch - W17641
Ref. GG-B100X-1A3ER
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 129 Casio watches in stock.The Mudmaster line was built for the kind of ground conditions that stop ordinary tool watches dead — mud, grit, debris forced into gaps by impact. This GG-B100X variant takes that architecture a step further by introducing bio-based resin into the case and strap construction, reducing dependence on petroleum-derived materials without compromising the Carbon Core Guard structure underneath. The three-layer bezel with carbon fibre inserts is a deliberate nod to off-road jerry cans, which is either a piece of design trivia or a useful reminder of the environment the watch is designed for, depending on how you use it. At 51.3mm wide and 19.4mm deep it is a large, assertive object on the wrist, but 93 grams is genuinely light for something built this way, and the integrated green strap with its structural resin inserts beneath the lugs distributes that weight better than a standard lug arrangement would. The sensor suite — compass, altimeter, thermometer, step counter — pairs with Bluetooth and the Casio app to log altitude and route data passively, which is where the feature list starts to justify its length for anyone working in the field rather than just wearing the watch there.
- Reference
- GG-B100X-1A3ER
- Brand
- Casio
- Collection
- G-Shock
- Case size
- 51.3mm
- Case thickness
- 19.4mm
- Case material
- Resin
- Case shape
- Round
- Dial
- Black
- Functions
- Stopwatch, Countdown timer, Alarm, Backlight, World time, Perpetual calendar, Bluetooth, Step counter, Compass, Thermometer, Altimeter, Dual display, Digital display
- Water resistance
- 200m
- Bracelet / strap
- Rubber strap
- Strap colour
- Green
- Retailer
- F.Hinds
Additional specifications
- Lug-to-lug
- 55.4mm
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.
Manufacturer’s guarantee
Best of 2 retailers
What the specifications mean
A watch built to be worn hard and got wet.
Strengths
- 200m water resistance, rated for actual diving
- 55.4mm lug-to-lug keeps the 51.3mm case wearable
- Luminous hands and markers for low light
- Second time zone for travelling
- One of Casio's more premium watches
Worth knowing
- 51.3mm is a large watch with real presence
- 19.4mm thick, so it will not disappear under a cuff
Compare alternatives
Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.
| Specification |  GG-B100X-1A3ER |  010-03020-03 |  DZ4629 |
|---|---|---|---|
| Price | £349 | £430 | £289 |
| Case size | 51.3mm | 50mm | 49mm |
| Water resistance | 200m | 100m | 50m |
| Movement | Quartz | Quartz | Quartz |
| Strap | Rubber strap | Silicone strap | Stainless steel bracelet |
| This watch |
|
|
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.
Will the glass scratch?
It can, over time. Mineral glass handles daily wear but will pick up fine scratches that sapphire would not.
Does it need a battery?
Yes. It is quartz, so expect a battery change every two to three years at a jeweller.
Will it fit my wrist?
Lug-to-lug is 55.4mm, which suits wrists from roughly 18.5cm (7¼ inches) upward.
Lug-to-lug decides fit more than case diameter does.
Is it a men's or women's watch?
Listed as men's.
Cheapest place to buy
Both F.Hinds and Goldsmiths list it at £349, so choose on delivery and warranty rather than price.
Who are F.Hinds?
F.Hinds has been run by the same family since 1856 and is now in its fifth generation, with more than 115 shops across England and Wales. They are a member of the Responsible Jewellery Council and an Authorised Diamond Dealer.
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