A chronograph with the reliability of Spring Drive The first ever Grand Seiko chronograph, this model is powered by a Grand Seiko’s unique Spring Drive caliber, which combines the motive force of a mainspring with the high precision of a quartz watch. The Spring Drive mechanism allows the watch to maintain precise timekeeping while also incorporating accurate chronograph capabilities, all with a maximum 72-hour (3-day) power reserve. Grand Seiko's original glide motion is also featured in the chronograph's blue steel second hand. The chronograph utilizes a Ready/Start button with a half-press shutter, to ensure the most precise possible operation, the chronograph start an stop buttons have a ‘ready’ stage so that the chronograph is armed by pressing the button half way.