The Tool Desk
Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →The Casio G-Shock GA-2100SRS-7A is a 2100-series analog-digital watch built around one unusual design choice: rainbow vapor deposition across its mineral glass. The treatment shifts color with the light, but Casio cautions that it can also make the dial hard to read from some viewing angles. Choose it for that changing, reflective look—not if effortless legibility is your top priority.
What makes the GA-2100SRS-7A different?
The defining feature is the crystal. Casio applies a rainbow vapor-deposition treatment to the glass, creating a shifting gradation rather than a fixed dial color. The appearance can vary from one watch to another, and the effect changes with the light. Casio’s own warning is direct: “Also, depending on the viewing angle of the watch, it may be difficult to read the dial.” Casio’s US product page and its Iridescent Color Series page describe the treatment and its visibility trade-off.
| # | Preview | Product | Price | |
|---|---|---|---|---|
| 1 |
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Casio - GA-2100BM-7A2ER GA-2100BM-7A2ER, G-Shock | $118.94 | Buy on Amazon |
| 2 |
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Casio G-Shock Octagonal Silver Dial Translucent Resin Watch GA2100BM-7A8 | $142.95 | Buy on Amazon |
| 3 |
|
G-Shock GA2100-7A White One Size | $104.98 | Buy on Amazon |
| 4 |
|
G-Shock Casio GMAP2100-7A Analog-Digital Bio Based Style Classic White Watch | $101.25 | Buy on Amazon |
That compromise defines the watch more than a conventional colorway would. The crystal is the visual focus, but reflections and viewing angle may compete with the hands and markers. The clear resin band and transparent case elements reinforce the light, colorful presentation rather than disguising it as a standard, high-contrast 2100.
How it looks in person, according to the hands-on coverage
In a July 3, 2023 hands-on article, Fratello’s Lex Stolk described the transparent resin case and strap as distinctive and light-looking, and the reflective crystal as exceptionally bright. Those are the reviewer’s aesthetic impressions, not independent measurements or a controlled legibility test. Read Stolk’s hands-on account at Fratello.
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The model is sometimes framed editorially as a transparent, iridescent “CasiOak,” a nickname drawn from the 2100 series’ shape. That is not Casio’s official model name. The official designation is GA-2100SRS-7A.
Specifications and everyday functions
| Specification | GA-2100SRS-7A |
|---|---|
| Display | Analog-digital |
| Case size | 48.5 × 45.4 × 11.8 mm (Casio specification) |
| Weight | 51 g (Casio specification) |
| Case and bezel | Carbon/resin with Carbon Core Guard construction |
| Band | Resin; listed fit range 145–215 mm |
| Glass | Mineral glass with rainbow vapor-deposition treatment; appearance may vary by watch |
| Water resistance | 200 meters (20 bar), per Casio |
| Shock resistance | Yes, per Casio |
| Power | Two SR726W batteries |
| Approximate battery life | Three years, per Casio |
| Series functions | Hand shift; world time for 48 cities; 1/100-second stopwatch; countdown timer; five daily alarms; double LED light |
The measurements, resistance ratings and battery estimate are manufacturer specifications, not independent test results. Casio lists the series functions on its Iridescent Color Series page. Although the watch has double LED light, that does not remove the crystal’s angle-dependent legibility caveat in ordinary viewing.
Rank #2
- Case size (L× W× H): 48.5 × 45.4 × 11.8 mm
- Case and bezel material: Carbon / Resin
- Construction: Shock Resistant, Carbon Core Guard structure | Band: resin band
- Weight: 51 g
- Water resistance: 200-meter water resistance
What to know before choosing it over another 2100
The GA-2100SRS-7A is best suited to someone who wants the treated crystal to dominate the watch’s appearance and is comfortable with a battery-powered, non-Bluetooth configuration. Casio’s comparison models illustrate some practical alternatives, though specifications and availability can change:
| Model | What Casio’s US comparison indicates |
|---|---|
| GA-2100SRS-7A | Rainbow-treated glass; two SR726W batteries; no Bluetooth or solar power listed |
| GA-B2100-1A | Solar powered and Bluetooth-equipped |
| GM-2100-1A | Listed as a comparison model; details not stated here |
| GM-B2100D-1A | Listed as a comparison model; details not stated here |
These are not interchangeable feature-for-feature alternatives based on the information above. Check Casio’s current model pages for the exact specifications, dial visibility, price and availability of any watch you are considering. The key decision is whether you prefer the SRS-7A’s color-shifting glass or would rather prioritize another feature, such as solar charging and Bluetooth on the GA-B2100-1A.
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- From Casio, this rugged G-Shock Carbon Core Guard Analog-Digital watch will toughen up your collection
- The case is made of fine resin embedded with carbon fibers, making the thin, lightweight, and simple design configuration of this model possible
Price and availability
When accessed for this article in 2026, Casio’s US product page listed the GA-2100SRS-7A at $145 and marked it sold out. That is a US listing observed at that time, not a guarantee of the current price or stock; check Casio’s product page for its latest status.
The series was announced by G-SHOCK Singapore on July 1, 2022, with online and in-store availability stated from July 8, 2022. Those were launch-era Singapore dates, not evidence of present-day availability elsewhere. G-SHOCK Singapore’s announcement provides that launch context.
Quick Recap
Rank #4
- Analog-Digital
- Band width: 5.0
- Watch movement type: Japanese Quartz
- Case diameter: 42.0
- Item shape: Octagonal
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.
