Solar powered by light energy</br>4-month power reserve once fully charged</br>Analog-quartz Movement</br>Case Diameter: 29mm</br>Water resistant to 30m (100ft): in general?? withstands splashes or brief immersion in water?? but not suitable for swimming or bathing</br><br/>http://www.amazon.com/gp/product/B01M9ECSZU