The toughest watch in the world is now the smartest watch in the world. The Atomic Solar G-Shock features Tough Solar Power and up to the second precision timekeeping. The Atomic Solar G-Shock is so smart and self-sufficient; you don't have to worry about changing its batteries or even setting the time. It's powered by a tough solar cell and sets the time itself using a receiver inside that picks up a radio frequency from the US Government's precise atomic clock in Fort Collins, Colorado. See manual for reception advice, including ideal conditions and interference factors. Shock resistant and water resistant to 200 meters.