http://www.thewatchbox.com Zenith's Pilot Type 20 Annual Calendar combines the legendary manufacture's competence in aviation watches and complicated chronographs. While the first Zenith pilot's watch crossed the English Channel in 1909 on the wrist of pioneering French aviator Louis Bleriot. By 1960, with the Cal. 5011 and the Type 20 chronometer, Zenith was entrenched as a pilot's manufacture of reference and a hallowed name in the annals of aviation history. Barely nine years after the release of the Type 20, Zenith's most celebrated product of all time, the automatic-winding El Primero chronograph movement, debuted. The combination of Zenith's aviation heritage and the El Primero's storied precision yields a compelling modern luxury package in the Type 20 Annual Calendar. The 48mm case of the Type 20 Annual Calendar recalls the oversized instrument watches constructed for aviators at the height of mid-twentieth century aviation. Its distinctive coined rectangular chronograph pushers and "onion: crown visually tie this Type 20 to an era when air travel retained all of the romance and air of adventure that inspired earlier generations to take flight. A large alligator leather strap with contrasting white stitching and pin buckle is exceptionally user friendly and completes the vintage effect. Inside the massive case, an El Primero Cal. 4054 annual calendar chronograph adds tremendous watchmaking content to the Type 20. Zenith is a true manufacture that fabricates each portion of its movements - hairsprings included. The familiar but still uncommon 36,000 VpH beat rate of the El Primero chronograph can be detected when held against the ear, and its furious chatter is the owner's assurance of outstanding precision. Each function of the chronograph engages crisply thanks to a time-tested column wheel selector - the mark of a traditionally manufactured chrono. But this El Primero is a champion among thoroughbreds. Its annual calendar complication has been designed in conjunction with the legendary Dr. Ludwig Oechslin. The brains behind the Ulysse Nardin Trilogy of Time, Freak, GMT Perpetual, and many other landmark complications here invests Zenith's signature chronograph with a share of his horological magic. Using an economy of components and an elegant three-aperture display, Oechslin enhances the El Primero with a user friendly annual calendar that requires only a single reset per year (February- March 1). This Zenith Type 20 Annual Calendar is available from thewatchbox.com indistinguishable from new and complete with every factory box, manual, supporting document, and accessory that a collector would receive from a Zenith factory boutique or authorized dealer. Video and content by Tim Mosso.