From my review
Review Details
This guide combines my hands-on verdict with the specifications and buying details above.
Specifications checked against the manufacturer.
Some versions are older and may be hard to find. Check the exact model and current stock before ordering.
THE CASIOAK
Shows the time in cities or time zones around the world. A second clock alone does not count.
A slim, tough G‑Shock that feels well made and sits comfortably on the wrist. The hands are clear, and the small weekday dial is handy. I loved my Hidden Glow dial at night. Compared with the SKMEI 2091, the Casio offers better build quality, a thinner case and hands that move both ways when setting the time.
Shop GA-2100 colours and check the model before buying. My review is of the Hidden Glow edition. Stock varies by country.
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A strong everyday and swimming rating, but always check the manufacturer’s guidance before diving.
Open the Full GuideFrom my review
This guide combines my hands-on verdict with the specifications and buying details above.
Specifications checked against the manufacturer.

Review evidence
I wore the grey GA-2100HD-8A Hidden Glow for a week. Here’s how it looked and felt on my wrist.
Watch the videoCompare the details
Compare the thinner, genuine G-Shock with the much cheaper SKMEI: its soft straps and larger buttons have advantages, but the construction, water rating and hand-setting behaviour differ.
Compare With the SKMEI 2091Choose your Casioak
I loved the glowing dial on my grey Hidden Glow edition. Its small dark screen was much harder to read. If you use the timer or alarms often, look for dark digits on a light screen.
Pick a colour you love, then check how easy its screen is to read. The glowing dial made the Hidden Glow my pick.
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