The company was originally founded as Shokosha Watch Research Institute in 1918 and is currently known as the manufacturer of calculators and small electronic organizers as well as Citizen watches. The trade name originated from a pocket watch Citizen sold in 1924.Eco-Drive is Citizen’s proprietary technology that powers watches using any natural or artificial light source. It drives the watch by incorporating a solar cell that generates electricity from captured light. Surplus electrical energy is stored in a rechargeable battery. This mechanism has earned an ecologically friendly reputation because it incorporates a rechargeable battery that does not use harmful metals and in manufacturing process no toxic substances are used .All Citizen Eco-Drive movements are made in Japan but the case or the bracelet may also be made in China. It’s Diving series (Promaster & Scuba) are best-selling worldwide.