Casio G-Shock “CasiOak” Showdown: GA-2100 vs. GA-B2100 vs. GM-B2100 – The Ultimate 2025 Guide
The GA-2100 debuted in 2019 as the original “CasiOak,” with an octagonal bezel and Carbon Core Guard resin, and at 11.8 mm thick became the slimmest G-Shock ever. The GA-B2100, released in 2022, adds Tough Solar and Bluetooth while preserving a 48.5 × 45.4 mm case and an 11.9 mm thickness, weighing about 52 g. The GA-B2100’s 9 o’clock sub-dial now indicates the mode and battery level, reflecting its solar-powered design, unlike the GA-2100’s day-of-week indicator. The GA-B2100 includes solar charging and Bluetooth smartphone linking, enabling auto time sync to the phone up to four times per day and a
