A legendary chronograph’s heir

Caliber 8R was born for precision.


An uncompromising spirit of craftsmanship handed down from one of the world’s first automatic chronographs.

Mechanical chronographs are known to require a high level of technical skill due to their complexity. A pioneer in automatic chronographs, Seiko debuted its legendary Speedtimer in 1969. Carrying this legacy forward, Seiko’s 8R series of chronograph movements employ a wide range of technologies that have been created and honed by Seiko over many years.

Features of the Movement

Vertical clutch

The vertical clutch eliminates shuddering or jumping of the hands when the start/stop button is pushed, enhancing the chronograph’s accuracy and durability. By stacking components on top of each other, the vertical clutch avoids the meshing of gears observed in horizontal clutch mechanisms.

Column wheel

The column wheel, which resembles the top of a castle turret, ensures precise control of chronograph operation. Using a column wheel leads to a better tactile sensation when starting, stopping, and resetting the chronograph compared to cam-and-lever constructions.

Three-pointed hammer

Seiko’s unique three-pointed hammer ensures that when the re-set pusher is pressed, all the hands return to zero instantly and in perfect synchronization. This provides a high level of durability and greater satisfaction for the user.

Caliber Number:

Movement Type:
Automatic with manual winding

+25 to -15 seconds per day

Power reserve:
Approx. 45 hours