The Casio G-Shock GMB2100 is the full-metal, bracelet-equipped take on the octagonal 2100 design. It combines a stainless-steel case, bezel and bracelet with G-SHOCK shock resistance, 200-meter water resistance, Tough Solar charging and Bluetooth connectivity. This review covers the family’s documented design and functions; the exact finish matters, so check the reference number before comparing listings.
What the GMB2100 is—and what it is not
Casio describes the GMB2100 as a Full Metal member of its 2100 line. Its case, bezel and band are stainless steel, while the watch keeps the octagonal silhouette associated with the series. That distinguishes it from metal-covered GM2100 models and 2100 variants with resin bands. The family’s design is described by Casio as derived from the DW-5000C, the original G-SHOCK introduced in 1983. Casio’s GMB2100BD-1A product page identifies one specific black-and-gold-tone finish; it should not be treated as the appearance or price of every GMB2100.
![Casio GM-B2100BD-1AJF [G-Shock GA-2100 Series Full Metal Model with Smartphone Link] Men's Watch Shipped from Japan Aug 2022 Model](https://m.media-amazon.com/images/I/41NKkEMv0-L._SL160_.jpg)
![Casio GM-2100BB-1AJF [G-Shock (G-Shock) Metal Covered Series Blackout] Watch Imported from Japan Feb 2023 Model, Black, Mens, Black, Modern](https://m.media-amazon.com/images/I/41YV+AJKF6L._SL160_.jpg)
Construction: metal outside, shock protection by design
The defining change from resin-band 2100 watches is the stainless-steel bracelet and metal case-and-bezel construction. Casio describes hairline and mirror finishing on the metal components, a screw-back case, and a one-touch three-fold clasp as features of the full-metal design or collection. Confirm the exact reference’s specifications before assuming every collection-level detail applies unchanged to a particular variant.
Full metal does not mean Casio has abandoned the shock-resistant structure. Casio says fine resin buffering components sit between the bezel and case to help protect the module, while a three-pronged lug structure disperses shock at the band connection. These are the manufacturer’s explanations of the construction, not independent impact-test findings. The available specifications do not establish how the finish wears, how readily the bracelet scratches, or how comfortable it feels in use.
#1 Best Overall
- Forged in stainless steel with rounded hairline finish, the strong bezel says super style all the way
- Super LED Light
- Shock Resistant
- Mineral Glass
Functions and connectivity
Casio lists the family’s core functions as follows. These are manufacturer specifications, not independently measured performance results.
- Power: Tough Solar charging.
- Connection: Bluetooth Smartphone Link.
- Timekeeping: World time for 38 cities, hand shift and a 1/100-second stopwatch.
- Timers and alarms: Countdown timer and five daily alarms.
- Visibility: Double LED illumination; Casio highlights a high-brightness LED on the GMB2100BD-1A page.
- Protection: G-SHOCK shock resistance and 200-meter (20-bar) water resistance.
Casio says its CASIO WATCHES app can support automatic time adjustment, watch-setting changes, world time for about 300 cities, time-and-place recording, reminders and a phone finder. Those are app capabilities described by the manufacturer; availability and operation can depend on region, app version and phone compatibility. Check the documentation for the precise model and your market before relying on a particular app function.
Rank #2
How to choose the right GMB2100 variant
There are multiple finishes and reference numbers in the family. Before purchasing, compare the exact model number on the watch listing with Casio’s page for that reference. This avoids confusing a bracelet-equipped full-metal model with a metal-covered watch or a resin-band variant, and makes it possible to confirm the finish and listed functions rather than extrapolating from a family description.
- Construction: Verify that the listing specifies stainless-steel case, bezel and band if you want the full-metal bracelet configuration.
- Finish: Check the reference number and product images; color and surface treatment differ across variants.
- Features: Confirm the model’s stated Tough Solar, Bluetooth, water-resistance and function details against its own product page.
- Price and stock: Treat each retailer’s current listing as specific to that reference, seller, region and date.
Price and availability
Casio’s US product listing for the GMB2100BD-1A showed $660.00 and a “NOTIFY ME” stock status in the listing snapshot available for this review. That is a time- and region-specific listing, not a guaranteed current price or indication of stock for other finishes. Check the exact reference on Casio’s site or with a retailer for current availability.
Recommended Free Tools
Rank #3
- Metal-clad daring meets sophisticated gleam in this Casio G-Shock that delivers Smartphone Link via Bluetooth(R) and Tough Solar charging system, all in a meticulously finished metal design with iconic octagonal bezel
- This model features a blue metallic vapor deposition dial that is complemented by a black band made of environmentally responsible bio-based resin
Who should consider it?
The GMB2100 is a candidate for someone who wants the octagonal 2100 look in an all-stainless-steel case, bezel and bracelet, while keeping the documented G-SHOCK protections and solar-and-Bluetooth feature set. A resin-band 2100 or metal-covered GM2100 is a different construction choice; compare those categories by materials, band, functions, water resistance and current price rather than assuming they are interchangeable. The manufacturer specifications do not settle questions such as comparative comfort, scratch resistance, accuracy or battery longevity, so those should not be inferred from the feature list.
Quick Recap
Best Value
- {"bullet_point1":"clip-on"}
- The rugged watch's 45.4mm case is expertly crafted from fine resin mixed with carbon fiber, an innovative composition that is lighter and more durable than resin
- The smooth black dial features an analog-digital display and double LED light feature, for easy visibility in the dark
Rank #4
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
