Powered by solar energy, the Casio G-Shock will run for as long as there is sunlight, allowing it to run endlessly. Not only does it give you the time, it also will give you the time in other parts of the world. Two more of its features include a stopwatch function and a countdown timer. The five daily alarms you can set will keep you on schedule as well. There is a battery-level indicator and a power-saving mode to ensure you get the most out of your time with this watch. Choose between a 12- or 24-hour format depending on your needs. Inside is a quartz movement that will reliably and accurately keep the time. Large and noticeable, the Casio Steel G-Shock boasts a case diameter of 59.1 millimeters.