Prospex Speedtimer

In the 1960s, Seiko entered the international sports timekeeping scene with a whole new generation of high-precision time measuring devices that were enthusiastically endorsed by many international sports federations and used to record time at many world sporting events.

At the heart of this success was a series of chronometers incorporating Seiko's innovative heart-shaped timing mechanism, a feature that offered a level of precision once thought impossible to achieve with manual chronometers.

Subsequently, in 1969, Seiko introduced the Seiko Speedtimer with the innovative 6139 calibre. It was the world's first automatic chronograph with a column wheel and a vertical clutch, two features that brought significant improvements in measuring the elapsed time of a wristwatch and that remain a requirement for high-functioning chronographs today.