From G-SHOCK, the watch that always strives for toughness, the first G-STEEL line-up models to offer chronograph performance in analogue format, but still maintain the G-SHOCK level of shock resistance. The GST-B100D features a solid case and simple stainless steel bracelet. The dial at 9 o'clock has a multi-functional rotating disk that is cut to resemble the thick blades of a jet engine. Rotation of the blades reveals red colouring behind the disk, and this change in colour is used to indicate the battery level and the alarm on/off setting. The blades also rotate in the Timekeeping and Stopwatch modes to with the passage of time. A new layer guard structure houses resin cushioning parts inside the case, for a more elegant design and a better fit to the wrist. High density mounting technology makes it possible to create a module that is smaller and thinner, which also contributes to a better fit. This watch is equipped with Bluetooth that lets it connect with a smartphone at the press of a button, and acquire time information from an internet time server. The result is accurate timekeeping no matter where in the world you happen to be. Other functions include a solar powered battery with up to two years power reserve, high brightness LED light illumination, and dual dial World Time.