Citizen Men's BM6030-91E Eco-Drive Stainless Steel Watch Light powered Eco-Drive Caliber E111 Japanese-quartz movement; Charges in natural sunlight or indoor light Max power reserve: 180 days; Low charge warning: 4 days; Quick start ability; Charge time from stop state to max charge: Incandescent Light - 120 hrs, Outdoors, Cloudy (10,000 Lux) - 35 hrs, Outdoors, Sunny (100,000 Lux) - 11 hrs Durable, hardened mineral crystal; Case diameter: 37 mm Stainless steel case; Black dial; Date function Water resistant to 99 feet (30 M): withstands rain and splashes of water, but not showering or submersion