The Casio G-SHOCK Octagon Bluetooth Solar GBM-2100A-1A3ER watch bases its operation on a state-of-the-art solar mechanism. The black plastic strap is combined here with a silver-colored envelope, for the manufacture of which glass-fiber-reinforced resin and stainless steel were used. Mineral glass is responsible for protecting the green dial. Product features include bluetooth, world time, power saving, find phone, mute, 5 daily alarms, perpetual calendar, stopwatch, timer and Super Illuminator backlight. The model is distinguished by shock resistance and 200-meter water resistance.
Functions
Bluetooth® Smart
The watch is equipped with energy-saving Bluetooth® technology, which offers power-saving data transfer at the push of a button. The watch can connect to a smartphone wirelessly via Bluetooth®, enabling access to a wide range of useful functions.
Super-Illuminator
At the touch of a button, the display can be brightly illuminated in a fashionable color
Shock-resistant
Shock-resistant construction protects against impact and vibration.
Solar Power
A solar cell provides power for operation.
Neo-display
A luminous coating provides long-term illumination in the dark after only a short exposure to light.
World time function
Displays the current time in major cities and specific areas around the world.
Stopwatch function - 1/100 sec. - 24 hours
Accuracy of measurement up to 1/100 of a second, measuring range up to 24 hours.
Timer - 1/1 sec. - 24 hours
For fans of precision: the countdown timers help you to remember specific or recurring events by giving off an audible signal at a preset time. They The time can be set to the nearest second and up to 24 hours in advance.
5 daily alarms
The daily alarm reminds you about recurring events with an acoustic signal at the time you have set. This model has 5 independent alarms for flexible reminders of important appointments.
Button tones on/off
The button tones for using the mode button can be turned off. This means that the watch no longer beeps when switching from one function to another. Preset alarm or countdown timers remain active when the button tones are deactivated.
Hand Moving Function
With a push of a button, hands are moving and permit a free visibility of functions like stopwatch or date.
Phone Finder
Misplaced your smartphone? All it takes is the push of a button on your watch and the smartphone sounds an alarm.
Flight Log Memory
The product is equipped with Flight Log Memory.
Automatic calendar with Date, Day and Month
Once set, the automatic calendar always displays the correct date.
12/24-hour timekeeping
Times can be displayed in either a 12-hour or 24-hour format.
Mineral glass
The tough mineral glass resists damages.
Folding clasp
The watch has a folding clasp.
Battery level indicator
An indicator shows the current battery level.
Water resistance classification (20 bar)
Perfect for free diving without scuba gear: the watch is water resistant up to 20 bar according to ISO 22810.
What’s in the box?
3-year warranty
User manual
Warranty card
Casio box
Reviews about G-SHOCK Octagon Bluetooth Solar GBM-2100A-1A3ER (8)
I was looking for a rugged watch for special missions, and this model completely met my expectations. The key factor in my decision to buy it was G-SHOCK’s legendary shock resistance combined with its impressive water resistance up to 200 meters. These specs give me total peace of mind—I take it on demanding expeditions, bike rides in rough terrain, or to the pool without a second thought, and I don’t have to worry at all that anything will happen to it. Plus, the steel, octagonal bezel gives it a great, rugged character, so the watch doesn’t look like just another plastic watch. The green dial pairs perfectly with the black strap, and the entire construction is compact and incredibly durable. For someone who needs reliable gear that can survive literally anything, this durability is an absolute masterpiece.
Sofokles
5/6/26
100%
Good service, fast delivery.
Adam M.
3/16/26
100%
I bought this watch for myself and I'm happy with it. I appreciate its reliability and the modern solar-powered mechanism that this brand is known for. It looks great and works flawlessly. I recommend it to everyone.
Majlo
3/2/26
100%
This is my latest G-SHOCK, but this Octagon model with Bluetooth and solar power takes convenience to a whole new level. The biggest plus is Tough Solar—the watch charges itself from light, so I don’t have to worry about replacing the battery for years. Syncing with my phone via Bluetooth is lightning-fast, which makes setting alarms or world time a breeze without the tedious clicking of buttons on the case. The green dial looks amazing in person, especially in the sun. The package from Zegarownia arrived in less than 24 hours, perfectly packed. I highly recommend it!
Matix
2/17/26
100%
For me, the biggest plus is Tough Solar—I don’t have to worry about changing the battery because the watch charges from just about any light source. Bluetooth works great, too, because setting the time or alarms via the phone app is super convenient—no fiddling with buttons. Even though it’s a G-SHOCK, it’s surprisingly slim and fits easily under a sweatshirt or jacket. The watch arrived in no time, and the option to extend the warranty to 6 years gives me total peace of mind.
Karol M.
11/20/25
100%
I bought this watch as a graduation gift for my sister. It’s very durable and attractive. It looks great on the wrist and has many useful features. The store offered free shipping, which I really appreciated. I’m happy with my purchase.
brzydUla
11/19/25
100%
I received this model as a gift. The plastic case is lightweight and durable. The watch is comfortable to wear and has a modern look. I recommend it.
mercdzik
9/9/25
100%
I received the package today—the watch is amazing. The photo doesn't do justice to the quality of the craftsmanship. I've already set it up and connected it to the app—it's fantastic. I highly recommend both the watch and the Zegarownia store.
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The administrator of your personal data is the owner of the Watchard store, i.e. 57 Concepts Sp. z o.o. Sp. k. with the registered office at al. Witosa 31, lok. 115, 00-710 Warsaw, Poland. Providing personal data by the Customer is voluntary but necessary to complete the purchase. You have the right to view your personal data we have processed, as well as the right to request changes or removal of your personal data. Personal data will be processed for a period of 10 years.
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The administrator of your personal data is the owner of the Watchard store, i.e. 57 Concepts Sp. z o.o. Sp. k. with the registered office at al. Witosa 31, lok. 115, 00-710 Warsaw, Poland. Providing personal data by the Customer is voluntary but necessary to complete the purchase. You have the right to view your personal data we have processed, as well as the right to request changes or removal of your personal data. Personal data will be processed for a period of 10 years.
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