The first G-SHOCK chronograph, GMC-B2100D-1A, made entirely of steel and with an octagonal case. A newcomer in the constantly evolving 2100 watch line. Buffering components made of fine resin are installed between the bezel and the case for a shock-resistant structure with a full-metal exterior. The bezel—formed three-dimensionally in a time-consuming forging, cutting and polishing process—is finished beautifully with a circular hairline treatment on the top surface and mirror polish on the slopes. The delicate moulding and vapour deposition of Casio ultra-precision processing technologies add sophistication and quality to the indexes and inset dial rings. The screw-lock crown is designed in the same octagonal shape as the bezel for a more compact case with no sacrifice in outstanding G-SHOCK shock resistance. High-density mounting keeps the module slim, while still providing the advanced functions you love in a compact profile and comfortable fit. Pairs with a smartphone via Bluetooth®. Simply tap into the dedicated app for precision timekeeping that keeps you on track. With Tough Solar, a high-brightness LED light and a range of other convenient functions, this is a timepiece that delivers both superior style and practical utility.