Atomic clocks are said to have an error of only 1 second every 100,000 years. A radio clock is a clock that receives standard radio waves transmitted from this atomic clock and automatically adjusts the time and date. By combining the power source of this radio-controlled clock with Eco-Drive, Citizen has created a clock that constantly keeps accurate time. There is no need to troublesome time adjustment or battery replacement. The secondary batteries used do not contain any harmful metals, and no harmful substances are used in the manufacturing process. Citizen technology is world-class and environmentally friendly.