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Casio

Casio G-Shock GA100-1A1 | Men's Tough Analog-Digital Watch | 200M Water Resistant | Shock & Magnetic Resistant | Sporty & Rugged Design

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Arrives Sep 4 – Sep 19
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Description

G-SHOCK GA100-1A1: The Ultimate Tough & Tactical Watch Designed for those who demand extreme durability and precision, the G-SHOCK GA100-1A1 is a rugged yet stylish timepiece that combines analog and digital displays for maximum functionality. Built with shock resistance, magnetic resistance, and 200-meter water resistance, this watch is engineered for military, athletes, outdoor adventurers, and extreme sports enthusiasts. The matte black resin case and band provide a stealthy, tactical look, while the oversized face and high- contrast digital-analog layout ensure easy readability. Whether you're timing a workout, tracking speed, or setting alarms, the GA100-1A1 delivers reliable performance in any environment. Equipped with a 1/1000-second stopwatch, speed indicator, and countdown timer, this G-SHOCK is perfect for training and competition. The LED backlight with afterglow ensures visibility in the dark, while five daily alarms and world time settings keep you on track across time zones. With its bold design, legendary toughness, and versatile functionality, the GA100-1A1 is not just a watch—it’s a statement of strength and endurance.

Is Discontinued By Manufacturer ‏ : ‎ No


Product Dimensions ‏ : ‎ 1 x 1 x 1 inches; 2.5 ounces


Item model number ‏ : ‎ GA-100-1A1DR (G270)


Department ‏ : ‎ mens


Batteries ‏ : ‎ 1 Lithium Metal batteries required. (included)


Date First Available ‏ : ‎ March 16, 2010


Manufacturer ‏ : ‎ Casio


Manufacturer’s warranty can be requested from customer service. Click here to make a request to customer service.:


Best Sellers Rank: #77,465 in Clothing, Shoes & Jewelry (See Top 100 in Clothing, Shoes & Jewelry) #210 in Men's Wrist Watches


Display: Analog-Digital


Watch Movement Type: Japanese Quartz


Additional Features: Alarm, Stopwatch, Timer


Power Source: Battery Powered


Strap Type: Removable


Water Resistance Depth: 200 Meters


Sport Type: Cycling, Hiking, Swimming


Clasp Type: Buckle


Water Resistance Level: Waterproof


Embellishment Feature: Crystal


Closure Type: Buckle


Style Name: X-Large GA100


Shape: Round


Band Color: Black


Dial Color: Black


Theme: Casio G-Shock


Pattern: Solid


Face Style: Simple black analog-digital


Character: Casio G-Shock watch X-Large Series


Brand Name: Casio


Model Name: G-Shock


Included Components: Casio GA100-1A1 XL Ana-Digi G-Shock


Model Number: GA-100-1A1DR (G270)


Item Weight: 2.5 Ounces


Global Trade Identification Number: 49


Manufacturer: Casio


Manufacturer Warranty Description: 1 Year Manufacturer


UPC: 627813137275 497185044385 079767443849


Manufacturer Part Number: GA100-1A1


Unit Count: 1 Piece


Age Range Description: Adult


Item Type Name: Watch


Band Material Type: Resin


Case Material Type: Resin


Crystal: Mineral Glass


Case Diameter: 51.2 Millimeters


Band Width: 21 Millimeters


Case Thickness: 16.9 Millimeters


Band Length: 7.5 Inches


Bands: 1


Warranty Type: Limited


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sep 4 – Sep 19

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

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Top Amazon Reviews

    • Excellent watch especially for the price. Excellent watch especially for the price.
Review Image by Fernando Arredondo Jr
Love it. It was simple to set up with the manual it comes with. Its a bit hard to read if you don't have sunlight but that doesn't bother me much because I love the black on black look. The band fits perfectly with plenty extra space and I'm a bigger dude so any big guys don't be scared to buy it. I don't plan to use it in water but the times its gotten wets its not been a problem. It a g-shock so you already know the quality and value are great. ... show more
Reviewed in the United States on May 14, 2026 Reviewed in the United States on May 14, 2026 by Fernando Arredondo Jr
    • Tough, reliable, and perfect for everyday use
I wanted a watch for my boyfriend that could handle anything without me having to baby it, and this one absolutely delivered. It has that classic rugged G-Shock look, but in person it looks even better — sleek, all-black, and very solid. It’s extremely durable. I’ve bumped it a few times at work and it didn’t get a single scratch. The shock resistance is no joke, and I love that it’s also magnetic-resistant and water-resistant up to 200M. My boyfriend showers, works out, or be out in the rain without worrying about it. The analog-digital combo is easy to read once you get used to it, and the backlight works great at night. It’s comfortable on the wrist despite being a larger watch, and the band feels strong and high quality. Overall, this is the kind of watch you buy once and keep for years. Reliable, tough, and stylish in a very simple way. Definitely worth it. ... show more
Reviewed in the United States on December 1, 2025 by Claudia Ko Chavez
    • Nice looking watch
Nice looking watch. Military style black out dial. Lightweight. A little hard to read the digital display but the white analog hands against the black are easy to read. No problems so far.
Reviewed in the United States on April 7, 2026 by Jon T.
    • Title: Built to Last – Outperforms Watches Twice the Price!
⭐⭐⭐⭐⭐ 5-Star Review This Casio G-Shock is hands down one of the best watches I’ve ever owned. It’s incredibly rugged and durable—I’ve put it through everything from yard work and workouts to weekend hikes and drops, and it still looks and performs like new. Programming it was super easy, even with the dual analog-digital display. The reinforced wrist strap feels secure and tough, no worries about wear or tearing over time. What really impressed me is how it’s held up better than some of the pricier watches I’ve had in the past. For the cost, this thing is unbeatable in performance, durability, and style. Highly recommend if you want a reliable, no-nonsense timepiece that can take a beating and keep ticking! ... show more
Reviewed in the United States on July 27, 2025 by Caree Simpson
    • Nice but a bit smol
All in all pretty sweet watch all around and easy to setup with Google video. Also, fairly comfortable. I was a bit disappointed in the size as i was hoping it was larger. It comes in at 52.8 MM . This is just personal pref though. Should have looked into the larger 55 MM GWB 1000's. Anyway fairly cool watch for sure. ... show more
Reviewed in the United States on February 24, 2026 by James W Tabor
    • Excellent watch for military Physical Training
There has been quite a few discussions on here regarding the quality of this watch and a line down the middle regarding the lighting of the watch's display and a very small portion of folks indicating that the time was never correct on the watch. To address the point almost half the reviews being made about the lighting, the watch display is lit by a single "amber" colored LED (to save power and provide a low light profile, I imagine) which provides more than adequate lighting for the analog hands on the watch to be viewed in pitch black darkness. The watch has a configuration option which allows you to modify the amount of time the LED light stays on from 1.5 to 3.0 seconds. The default time was sufficient for me to view the time but others may find the additional time convenient. This additional time may be what supplements the ability to view the digital time easier. Another owner of this watch indicated that placing an finger across the watch face from 9 to 3 (across the horizontal horizon) allows for the illumination to better reflect back onto the digital display for easier reading. I concur with this assessment and was able to read the time with both the 1.5 and 3.0 second configuration. This is not to say that the time on the digital display is what I would personally be using in low light conditions but it is definitely possible. Finally, the last point to discuss is the settings of the watch and the provided instruction manual in the packaging. Some have complained that the instructions are far too exhaustive due to the instruction manual being of significant length. To these people I say, "Did you even try cycling through the pages?" The instructions that came with my watch came with at least 4-6 different languages so that others that do not read english could take advantage of this product. The english instructions were probably about 40 pages to include the table of contents and some "Care Instructions". I was able to configure the analogue portion of the watch and the world time (to include modifying the Daylight Savings Time setting) in roughly 5-10 minutes at the most. Those that were unable to properly set this watch either did not focus on the various time zones that are clearly identified in the manual, or did not properly configure the Daylight Savings Time option for their time zone. I can say with great confidence that this watch will more than likely be used very much for work, play and the military and hope that it serves me for a long time because it is a great looking watch. Additionally, for those concerned about the size of the watch, it does have a good size in circumference and height off the wrist, but nothing out of the ordinary such as watches from Invicta dive watches. The weight of the watch is very light for me but I am accustomed to watches made of steel with a steel band and that may be causing me to think the watch is light in weight. Hopefully this conveys a very descriptive point of view regarding this watch and points out the supposed "flaws" others have portrayed in their reviews. ... show more
Reviewed in the United States on September 9, 2014 by Rogelio Fiorenzano
    • "THE 4-WHEEL DRIVE" OF WATCHES
I have read some reviews regarding this watch, but one review, in particular, influenced my decision to purchase the watch -- that being to overlook criticisms of not being able to read the digital date and time due to being either too small or too dark. The bright white hands make the time very visible, even under low-light conditions. Because the 'minute-second' markings are subdued, it difficult to see the minute-second markings or use the various digital features programmed into this watch in low-light conditions. The major plusses? I love the bright hands, easy time setting, plus, Casio's durable "G-Shock "™ quality and reliable accuracy. The "icing on the cake" is that this watch is light weight and stays in place on my wrist, rather than tries to roll away from me, as do other watches, especially, the heavier brands and models. My review supports a featured contributor who replied that the dark face was a minor issue, simply because, We CAN read the digital display without any problem in certain lighting, such as fluorescent-type. The type of lighting you're under, when viewing, will play a major factor regarding the visibility of the digital window data. Another point, the broad hands sometimes get in the way when observing the digital windows, making it difficult to rely on the available data and/or programmed features. Don't get me wrong, I LOVE the broad bright visible hand design on this watch, but I'm just saying there is a "trade-off that each prospective owner should consider. Recapping, I would say the basis of a purchaser's decision to purchase this watch is going to depend on the frequency-priority of viewing the digital display. If you need constant assurance about what day it is, or if you want to constantly read the digital display features, I say buy a digital watch and save yourself the frustration. If you're on the go, such as a delivery person, or doing housework, subject to occasional rough conditions and you want to frequently glance at the time with "no-nonsense" reliability, I highly recommend considering this model. The watch has a stealthy look which I think is simplistically attractive in our modern times. One more plus is the fact that you set the time, digitally, first, and the analog hands will respond to the digital setting. Love it! You don't have to mess with trying to match the separate times of the analogue-digital displays. Would I buy this watch, again? To be 'punny', "In a second"! ... show more
Reviewed in the United States on July 24, 2017 by Stan-The Man
    • Great watch. Great watch.
Review Image by Bryan Gonzalez
Great watch at an excellent price. The only downside was the delayed delivery, but other than that definitely recommend it.
Reviewed in the United States on April 3, 2026 Reviewed in the United States on April 3, 2026 by Bryan Gonzalez

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