Girard Perregaux pour Ferrari ref:9015 split second chronograph (chronographe à rattrapante in French).
What is a split second chronograph ?
Take a look at the pics and you will see two seconds hands.
First push the start button located at two o'clock.It releases both hands.One hand is superimposed over the other. You can stop one hand with the eight o'clock button to check the elapsed time while the other one continues to register the time. Push again the eight o'clock button and the second hand will catch up the first one.
