The watch can connect to a smartphone wirelessly via Bluetooth®, enabling access to a wide range of useful functions. Loading… RatingLet us know what you think about the Casio G-Shock GA-B2100C-9AER Watch by leaving a product rating. The Tough Solar charging system effectively converts light from any light source to power the watch, eliminating the need to replace the battery, and Smartphone pairing via Bluetooth® delivers accurate timekeeping.

Another advantage over the GA-2100 is that the date format is adjustable to the international style and the day of week language is available in six languages. An accessory that, along with beach volleyball and snorkel mask, is essential for the perfect beach day. The watches also retain the interior carbon fiber construction, which enables the GA-B200 to keep its durability despite the thinner dimensions.

In my experience with Bluetooth-enabled G-Shock watches, it's been extremely easy to forget it's even an option until I actually need to do something like setting an alarm on the watch or adjusting the time. Yellow with standard LCD display, black IP buckle, and black band keeper, based on the color scheme of DW-5600C-9BV from 1987. The series will launch with five models inspired by the classic first colors of early DW-5600 models. Nevertheless, those who want to do without looking at their cell phone don’t have to limit themselves.

The three models Casio G-SHOCK GA-B2100C-9AER (yellow), Casio G-SHOCK GA-B2100-1AER (black) and Casio G-SHOCK GA-B2100-2AER (blue) made the start this year. Combining the Carbon Core Guard structure, which protects the module and provides both shock resistance and a compact case, with G-SHOCK classic colours first used in the G-SHOCK 5600 models enables you to wear the latest, and the greatest G-SHOCK has to offer. And to come back to the summer watch suitability: Water resistance up to 20 bar makes the G-SHOCK GA-B2100C-9AER a very robust companion on the wrist. Not only can it ruin the delicate inner workings of your timepiece, but it can also make it look like it's been through a washing machine. I own about a dozen G-Shocks and they're almost evenly split between current-spec models featuring upgraded tech, such as Tough Solar, Bluetooth, and Multi-Band 6 atomic timekeeping (a feature I wish made it onto the GA-B2100, in all honestly), and more old-school designs that keep things basic with a simple multifunction battery-powered quartz movement.

The GA-B2100 series is unprecedented in some ways, as it is the first “GA-B” model and the first “GA-” model with Tough Solar power. Battling the laws of nature, founder Kikuo Ibe went on a mission to create a watch that resists impact forces including high water pressure and more.