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. 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. GA-B2100C-9AER is a stand out yellow colour, styled to be noticed.