Citizen Men's BL5365-51E Eco-Drive Perpetual Calendar Black Ion-Plated Sport Watch Light powered Eco-Drive Caliber E81* Japanese-quartz movement; Charges in natural sunlight or indoor light Max power reserve: 120 - 270 days with Power Save; Low charge warning: 5 days; Charge time from stop state to max charge: Incandescent Light - 43 hrs, Outdoors, Cloudy (10,000 Lux) - 12 hrs, Outdoors, Sunny (100,000 Lux) - 4 hrs Durable, hardened mineral crystal; Case diameter: 45 mm Stainless-steel case; Black dial; Perpetual-calendar functions Water resistant to 660 feet (200 M): suitable for recreational scuba diving