Citizen Eco-Drive x Analog ft. Elegance aka Blue Glow Night Men Formal Hexagon 100m Water Resistant Watch BM7631-87M BM7631 BM-7631Discover the Citizen BM7631-87M men watch, featuring a vibrant turquoise dial and stainless steel construction. Powered by light with Eco-Drive technology, it never needs a battery change. This 41mm sports watch offers 10 bar water resistance and a 6-month power reserve for effortless, reliable timekeeping.Caliber Number / MovementE111 (Eco-Drive aka solar powered)Power Reserve / AccuracyApproximately 6 months when fully charged (+/-15 seconds per month)CrystalMineral crystalLuminousLuminous on dial, hands and indexesCase / Band MaterialStainless steel case with stainless steel band (three-fold clasp with push-button release)Water Resistance100m / 10 barCase SizeThickness: 9.7 mmDiameter: 41.0 mmLength: 48.4 mmLug width: 22.0 mmOther SpecificationsCitizen Eco-Drive x Analog ft. Elegance aka Blue Glow NightScrew case backInsufficient charge warning functionOvercharge prevention functionDate displayRegular timekeeping (analog display)