sailboat that won the 1934 America's Cup. Sporto Stellina Movements El Primero The El Primero calibre, when it was first unveiled on January 10, 1969, it was the first high frequency automatic chronograph movement, and certainly the one to put Zenith Watches on the map. One of the original watchmakers who worked on the movement, Charles Vermot took upon himself to save the brilliant calibre when the owners of the brand decided to abandon the idea of a mechanical chronograph and focus on Quartz timepieces in 1975. While all the tools, components etc. used to manufacture the calibre were being dumped or sold, Vermot gathered all the necessary technical plans and tools and hid them in a walled-off attic at the Zenith manufacture to protect the El Primero for future generations. A decade later, when it was resurrected in 1986. the same tools, plans and components helped start the production of the El Primero again. It was one of the first automatic chronograph movements and has a frequency of 36,000 vibrations per hour (5 Hz). Zenith's El Primero movement was used by Rolex from 1988 to 2000 for the Rolex Daytona chronograph. The El Primero movement's high rate allows a resolution of of a second and a potential for greater positional accuracy over the more common standard frequency of 28,800 vibrations per hour (4 Hz). The El Primero was honoured with a 2012 release of the El Primero Stratos Flyback Striking 10th, limited to 1,969 pieces (in honour of the original 1969 release date), that housed the same 36,000 vph movement and a sub-dial measuring in tenths of a second to make a complete rotation every ten seconds. Elite In 1991, Zenith began development of a modular, slim, adaptable, and multipurpose in-house movement that could be housed within a wide variety of timepieces across their various collections. Lead by technical director Jean-Pierre Gerber, and aided by the manufacturer's first utilization of CAD, they developed an ultra-thin movement that ranged from 2.83mm to 6.20mm of thickness, depending on the inclusion of complications. Operating at 28,800 vibrations per hour (4 Hz), and featuring an annual Glucydur balance wheel, a self-compensating balance spring, and an automatic winding system with a large diameter tungsten carbide rotor mounted on ball bearings, the movement was designed for precision timekeeping that required minimal maintenance. When introduced at BaselWorld in 1994, it was awarded the title of "Best