The Casio G-SHOCK Gravitymaster Dual Time Solar GR-B300EC-1AER is a men's timepiece that combines advanced technology with durability, ideal for lovers of extreme conditions. The black envelope and strap made of durable resin provide resistance to damage, while the gray display adds modern style. The watch has features such as Bluetooth® Smart, solar power, Super Illuminator, shock resistance and Dual Time Display system. The watch also offers advanced features such as a crown lock, charge indicator, Flight Log Memory and water resistance up to 200 meters, making the Casio GR-B300EC-1AER an excellent choice for travelers and extreme sports enthusiasts.
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.
Dual Time Display
Dual Time simultaneously displays the time in two different time zones.
Date and weekday display
The current day and weekday are both displayed.
Stopwatch function - 24 hours
Elapsed times are measures with split-second accuracy. The watch can measure times of up to 24 hours.
Timer - 1/1 min. - 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. The time can be set to the nearest seconds and up to 24 hours in advance. This model has three independent timers - ideal for people who need to take medicines every day or those who do interval training.
Daily alarm
The daily alarm reminds you of events that recur every day, by emitting an audible signal at the set time.
Crown button lock
Secures the crown button from accidental change to another mode of operation.
Smart Access Technology
Smart Access makes it easy to operate CASIO’s watches. Pulling out and rotating the crown provides intuitive control over various functions.
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.
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 Gravitymaster Dual Time Solar GR-B300EC-1AER (7)
A reliable choice for everyday use. The sturdy black rubber strap works well in any situation.
Erros
3/31/26
100%
I gave this watch to my boyfriend for Valentine's Day. It has a comfortable rubber strap and looks great. It's a great gift! Lots of payment options.
Marianna M
3/10/26
100%
In person, the watch looks even more impressive than in the photos. The gray dial paired with the black case gives it a very modern, "aviation" vibe. This is my first Gravitymaster, and I’m impressed by the build quality—you can tell it’s a premium model that will withstand literally anything. I really appreciate the Dual Time feature, because I travel often and having a second time zone displayed on the dial is super practical for me. As for the purchase—free shipping and the option to extend the warranty for another 3 years ultimately convinced me to choose this store.
Gregos
2/5/26
100%
The product is well-balanced and crafted with attention to the finest details, a feature that any discerning user will appreciate.
Emilkan.
1/8/26
100%
Super-fast delivery, great product.
Grzegorz W
11/29/25
100%
Everything arrived on time, and the quality is great.
zbych
10/27/25
100%
The watch is quite large, which may be less comfortable for people with slender wrists—I’ve noticed this myself; at times, it clearly rubs against the cuff. The dual-time function (displaying the time in two time zones) works great—perfect if you occasionally travel or communicate with people in different time zones. Using the “CASIO Watches” app, I set the second time zone for my home and local time zones – it’s very intuitive. Bluetooth connectivity makes adjusting settings more convenient than traditional dials – which is very comfortable in everyday use.
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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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