Perpetual Calendar Automatically Adjusts for Oddand Even Months and Leap Years through 2100 Charges in Sunlight or Indoors - No Batteries to Change - Ever! When Fully Charged has a 500 Day Power Reserve Solid Stainless Steel Case Leather Strap with Push-button Deployment Buckle 12/24 Hour Time Day & Date display When in calendar mode, second hand points to the month on the inner bezel Dual Time Daily Alarm Low Charge Indicator & Time Reset Advisory in the Event it Ever Needs Charging Screw-Back Case Non-reflective scratch-resistant mineral crystal 100 Meter Water-Resistant Approximate dimensions: 38mm (1 1/2 inches) wide not including setting crown and 10.5mm thick