Zenith, EL PRIMERO series, model: 24.2041.400 / 21.R576, automatic mechanical movement, black ceramic aluminum, case diameter: 42mm, equipped with the legendary El Primero 400B automatic chronograph movement, with a frequency of up to 36,000 vibrations per hour, it is the first mass-produced high-frequency automatic chronograph movement in history. The chronograph accuracy can reach 1 / 10 second, the power reserve is approximately 50 hours, the lightweight black ceramic aluminum case, complete set, unused stock.