Specification : Perpetual Calendar with leap year correct until February 28, 2100. Time relay system preserves accurate time for up to 4 years. When the watch senses 24 hours of inactivity, it puts itself into suspended animation (sleep mode) to conserve energy. The date continues to advance correctly while the watch is asleep. Wake it up with a few shakes of your wrist and it automatically resets itself to the correct time even if it has been asleep for up to 4 Years. Movement Kinetic (no battery required). Powered by the movement of your hand. 24 hour hand Month hand Calibre 7D56 Leap year hand (7D46 / 7D56) Leap year disc (7D56) Power save function Accuracy 15 sec/month Water resistance 100m Movement from Japan Scratch resistant Sapphire crystal Stainless steel case Diameter 42mm Thickness 12mm