PROSPEX SPEEDTIMER MECHANICAL CHRONOGRAPH Prospex Speedtimer Mechanical Chronograph. Seiko Prospex challenges every limit with timepieces created to exceed expectations, engineered with superior style and innovative technology for the sea, sky or land. Driven by a heritage of iconic design, Prospex continues to keep going forward with excellence in precision timekeeping, crafted for the modern world. Based on Seiko’s Speedtimer chronographs of the early 1970’s, this powerful creation offers superior timekeeping combined with sporty elegance and wearing comfort. Providing chronograph measurement of up to 12 hours of elapsed time in 1/8-second increments, the proprietary caliber 8R48 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. The movement incorporates a column wheel and vertical clutch mechanism allowing for smooth, stutter-free movement of the chronograph hand while providing long-term efficiency, reducing wear and tear, and maintaining the power reserve during chronograph operation. For reliable timing, the three-pointed hammer system ensures that all hands return to zero instantly and in perfect synchronization when the re-set pusher is pressed. The black dial, framed by a tachymeter scale for an authentic look, displays the word “Speedtimer,” honoring Seiko’s sports timing legacy, and features subdials with a contrasting finish, a date calendar, and LumiBrite hands and markers for superior visibility in low-light conditions. Comes with a box and all the papers, ready to ship, unworn and like new.