Seiko Chronograph SSB139 SSB139P1 SSB139P Men's Watch

It is a meca-quartz chronograph but the hybrid construction is different from a Seiko Kinetic. It’s a regular quartz-based, electronic movement with a chronograph module made the way it is in a mechanical chronograph. There are two, small stepper-motors driving the primary timekeeping hands and the chronograph hands each. There’s a gear-train that helps the higher frequency of the chronograph to run the chronograph hands; giving it a smooth sweep and a greater precision than full seconds. Even resetting is a smooth and instantaneous affair due to a a heart-shaped cam like in the mechanical chronographs.