Citizen’s simple yet revolutionary Eco-Drive technology harnesses the power of light, whether natural or artificial, and converts it into energy, storing the surplus in a power cell. Designed to charge from any form of light source, from sunlight to desk lamps, you can go about your daily life and be confident that your Eco-Drive won’t stop. This Citizen Corso mens watch features a stainless steel 40mm round case, a classic black leather strap and a black dial with date window. Ref: AU1040.08E Product InformationBrand: Citizen Eco-Drive Caliber number J165Case Material: Stainless SteelCase Size: 40mmType of Strap: Black Leather Glass Material: Sapphire CrystalDial: BlackWater Resistant: 30mGender: Mens