Stunning the community with their groundbreaking release of the El Primero in 1969, Zenith innovated one of the most important self-winding chronograph calibers of the 20th century. As the very first self-winding chronograph wristwatch manufactured by the firm, the production of the El Primero was temporary ceased in 1975 amidst the devastating Quartz crisis. With an order from above to demolish the machinery, blueprint and basically anything to do with the build of the El Primero, it was believed for a second that mechanical watches were no longer necessary.