The Bering Slim Solar collection beats to the rhythm of nature! Because its energy source is environmentally friendly and infinitely available: light! Not only sunlight but any kind of light is converted into electrical energy by the solar cell under the face and stored in a rechargeable secondary battery. No battery change is required as in quartz watches. The watch has a power reserve, so that - once fully charged it runs for 6 to 12 months. Even if it is stored in complete darkness during this time. Scratch-resistant sapphire crystal. Number of Batteries: 1 Included: 1 Watch(es) Features: Solar Powered, Quick Ship Battery Type: Lithium Cells Jewelry Closure: Fold Over Clasp Power Source: Battery (included) Watch Movement: Quartz Water Resistance: 50m Band Color: Blue Dial Color: Blue Metal Color: Black Case Thickness: 9mm Case Width: 42mm Watch Band Length: 7 3/8 Inch Band Content: Stainless Steel Case Materials: 100% Stainless Steel Band Width: 22mm Care: Wipe Clean Country of Origin: Imported Quick Ship items ship directly from the manufacturer within 3 to 5 business days. Photos are enlarged to show detail.