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 Calendrier mens watch is sophisticated and functional. Featuring a 12/24 hour time, world time in 24 cities and day/date, the dark brown leather strap, rose gold PVD 44mm case and black face make this a timeless watch. Ref: BU2023.04E Product InformationBrand: Citizen Eco-Drive Caliber number E111Case Material: Rose Gold PVDCase Size: 44mmType of Strap: Brown Leather Glass Material: Sapphire CrystalDial: BlackWater Resistant: 100mGender: Mens