Prospex Speedtimer Mechanical Chronograph. 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. Framed by a tachymeter ring, the vivid blue dial with red and white accents and contrasting subdials recalls the colors of Seiko's original automatic chronographs. The proprietary 8R46 movement includes a column wheel and vertical clutch mechanism allowing for smooth, stutter-free movement of the chronograph hand while providing longer wear and efficiency, and improving maintenance of the power reserve during chronograph operation. Crafted of stainless steel with super-hard coating, specially designed pushers and crown for ease of use, tri-fold push button release clasp, and dual curved sapphire crystal with anti-reflective coating on the inner surface, this extraordinary timepiece also offers an additional black leather strap, and is packaged in a special collectors' box. 10 bar, 100M Water Resistant