Casio G-Shock GM-2100BB-1AER
The CasiOak wrapped in a layer of steel: everything that made the GA-2100 likeable, now with a little weight on your wrist.
The GM-2100BB-1AER takes the beloved octagonal 'CasiOak' shape and dresses it up with a genuine steel bezel in matte black. That instantly makes it feel more grown-up than the pure resin version, while you still stay under full-metal money. If the heavier GM-B2100 is too much watch, this hits the sweet spot.
Reasons to buy
- The steel bezel with its mixed brushed-and-polished finish looks surprisingly premium, especially in the blacked-out IP coating
- At 72 grams and 11.8 mm thick it wears light and slides easily under a cuff
- Combi dial with analog hands and a digital window: day, date, world time, stopwatch and five alarms
- 200 m water resistance plus the usual G-Shock toughness, so you can knock it around without worry
Reasons to consider
- The polished facets on the bezel pick up scratches more readily than you'd like; a few months in, you'll notice them
- Quartz running on SR726W cells rather than Tough Solar, so a battery swap every three years or so
- Mineral crystal instead of sapphire, which still feels like a miss at this price
Why that steel bezel changes everything
The whole trick of the GM-2100 is the bezel. Casio caps the familiar octagonal case with steel, giving it a circular-brushed top and polished sides. That play of matte and gloss is exactly what the resin CasiOak lacked: in the flesh the bezel catches light in a way that makes the whole watch read pricier than it is. In the all-black BB version, with a black ion coating over the steel, you get a clean, stealthy look that works as well with a suit as with a hoodie. Underneath it's still a G-Shock: the core is resin with steel wrapped around it. That's why it stays a featherweight 72 grams and a slim 11.8 mm. Reviewers don't call the GM versions 'the cream of the Casioak crop' for nothing โ you pay a premium over the plain GA-2100, but far less than the full-metal sibling or a separate mod kit.
Features and everyday use
Under the mineral crystal sits caliber 5611: a no-nonsense quartz module with no Bluetooth or solar bells and whistles. What you do get is plenty for daily life โ world time, stopwatch, countdown timer, five daily alarms and a day-date window, plus an LED backlight for the dark. The hands and indices glow, though as with most analog G-Shocks the lume is fairly modest. The honest catch: this is a battery watch. Two SR726W cells last around three years before it needs opening up. And watch the polished bezel surfaces โ several testers report scratches creeping in over time. The recessed crystal itself stays well protected, just like on the GA-2100.
Who is it for?
Great for anyone who already likes the CasiOak look but wants more wrist presence and a higher-end feel without committing to full-metal. Skip it if you specifically want sapphire glass, solar power, or a connected watch โ then the GM-B2100 or another segment makes more sense.
FAQ
Is this a full-metal watch?
No. The bezel is steel with a black ion coating, but the case beneath it and the strap are resin. That's why it looks tough yet stays a light 72 grams. For full metal you'd want the GM-B2100.
Does the GM-2100BB-1AER have Bluetooth or solar charging?
Neither, actually. It's a straightforward quartz (caliber 5611) running on button cells that last about three years. No app pairing, no Tough Solar.
