The solar cell below the sphere transforms into electric energy not only the light of the sun but any type of light and stores it in a rechargeable secondary battery, that is to say an accumulator. This means that it is not necessary to change the battery as it does with quartz watches.The watch has a power reserve so that if it is fully charged it can work between 6 and 12 months. Even if during this time it is kept in absolute darkness.Scratch-resistant sapphire crystal, brushed stainless steel, very elegant bracelet straps made of calfskin or Milanese mesh.