Designed for those who treat life as the ultimate adventure, the Seiko Prospex line meets every challenge with technological excellence and style. Celebrating Seiko's first precision chronographs, developed for international sporting competitions in 1964, as well as its 1969 introduction of the world's first automatic chronograph, this distinctive watch provides chronograph measurement of up to 30 minutes of elapsed time in 1/8-second increments. Visible through the screwdown, see-through caseback, the 34-jewel automatic movement beats at a frequency of 28,800 vibrations per hour, with a power reserve of approximately 45 hours and manual winding capability.