From the Prospex CollectionSolar diver's watchPowered by light energy - no battery change required10-month power reserve once fully chargedBlue uni-directional rotating elapsed timing bezelBlue sunray finish dialDate calendarLumiBrite hands and markersSapphire crystalScrewdown crown and casebackCase diameter: 38.5mmStainless steel case and braceletTri-fold push button release clasp with secure lock and extenderWater-resistant to 200 meters (660 feet), Diver's Watch. Follows ISO standards and is suitable for scuba divingCaliber V147