To mark the 40th anniversary of the launch of its proprietary Eco-Drive quartz technology, Citizen has created an extraordinarily thin watch with a case just 2.98 mm thick. The watch, called Citizen Eco-Drive One, is the world’s thinnest light-powered analog watch. Eco-Drive watches use natural or artificial light to generate their own electrical energy, eliminating the need to replace the battery.
The movement in Eco-Drive One, Caliber 8826, is a mere 1.00 mm thick. To get the requisite thinness, Citizen says it redesigned almost every part of the movement. The movement has an accuracy of +/-15 seconds per month. Citizen also reduced the energy consumption of the movement, enabling the watch to run for 10 months on a single full charge.
To create such a thin case, Citizen said it had to turn to new materials that are both thin and strong. It showcases these materials on an 800-piece limited-edition collection of Eco-Drive One. The case, which has a diameter of 38.15 mm, is made of cermet; the bezel is made from a cemented carbide. The company describes cermet as “an advanced composite composed of ceramic and metallic materials.” Binderless cemented carbide has superior hardness and is resistant to corrosion and oxidation. It is made mainly of tungsten carbide powder with no metallic binder like cobalt or nickel. The watches have a black crocodile leather strap. The suggested retail price is $6,000.
Citizen is also producing non-limited versions of the Eco-Drive One. These have slightly larger (39.8 mm) cases with the same 2.98-mm thinness, made out of stainless steel treated with a surface-hardening technology developed by Citizen called Duratect. On these watches, the bezel is made of cermet. The watches have bracelets made of Duratect-treated stainless steel. They are priced at $2,600. Duratect, Citizen says, maintains the luster and finish on watches by improving the surface hardness of the material, making cases and bracelets more scratch-resistant.
Eco-Drive One marks a new synthesis of beauty and technology at Citizen, according to Citizen Group CEO Toshio Tokura. “We are proud of our technology and precision,” Tokura told WatchTime. “But we have this other strand of pursuing beauty and we’re trying to combine the two. It’s not just Eco-Drive technology that allows us to make the watch more beautiful, but surface-coating technology. This watch is all about beauty.”
Scroll down to see live photos from Baselworld of the Citizen Eco-Drive One and its movement.