Casio G-Shock GA100B-4A Analog-Digital Black Dial Watch

Casio GA100B-4A: The Loud One

G-Shock built its reputation on being tough enough to survive anything. The GA-100 series adds “big enough to notice” to that list. The 4A variant in red takes an already bold design and removes any chance of subtlety. If that’s what you’re looking for, mission accomplished.

Size That Means It

At 55mm lug-to-lug and 16.9mm thick, this isn’t a watch that pretends to be small. The red resin case dominates your wrist intentionally—the GA-100 was designed for presence. The matte finish keeps it from looking cheap despite the bold color. “G-SHOCK” and “PROTECTION” text on the bezel aren’t subtle about what this watch is built for.

Analog Meets Digital

The combo dial puts analog hour and minute hands over a digital display at 6 o’clock. You get quick glanceability from the analog hands and precision timing from the digital. The speed indicator at 9 o’clock ties into the 1/1000-second stopwatch—actually useful if you’re timing things that matter. World time, countdown timer, five alarms, and full auto calendar round out the feature set.

G-Shock Tough

200m water resistance means actual swimming and diving, not just hand washing. Shock resistance is the G-Shock signature—the hollow case construction absorbs impacts that would kill lesser watches. Magnetic resistance (JIS Class 1) adds another layer of protection. Amber LED backlight handles low-light reading. Battery life is about 2 years on the CR1220—reasonable for the feature set.

Who Wears Red

The GA100B-4A is for people who want their G-Shock noticed. At $135, it’s an affordable entry into the GA-100 line with all the toughness the series is known for. If you need something you can actually abuse without worrying about it—and you want that something to be red—this is the watch.