In the 1960’s, Seiko entered the international sports timing stage with a whole new generation of high-precision equipment that was enthusiastically endorsed by many international sports federations and used to capture elapsed time at many of the world’s leading sports events. A range of stopwatches were introduced with Seiko’s innovative “heart-shaped cam” mechanism, a feature which delivered a level of precision once thought unachievable by manual sports timing devices. The 1964 Crown Chronograph was designed from scratch and it marked the beginning of Seiko’s chronograph wristwatch manufacturing. It had a simple one-push mechanism but it amply demonstrated the same commitment to precision. Then, in 1969, Seiko introduced the Caliber 6139 Seiko Speedtimer, the world’s first automatic chronograph with a column wheel and vertical clutch, two devices that revolutionized the measurement of elapsed time and are still prerequisites in modern automatic chronographs. A new series of automatic chronographs inspired by the Seiko Speedtimer and Seiko’s rich and continuing tradition of sports timing join the Prospex collection.