The CHRONOMASTER Original is crafted in a 38mm steel case in the same proportions as the A386, paired with the iconic tri-colour dial and a steel bracelet. Powered by the El Primero 3600 automatic high-frequency chronograph movement with 1/10th of a second chronograph function and a power reserve of 60 hours. THE RETURN OF A CHRONOGRAPH ICON Over 50 years After the launch of the seminal El Primero calibre, the CHRONOMASTER Original marks the latest generation of the movement with 1/10th of a second chronograph function in watch that's faithful to the A386 in style and substance. EL PRIMERO 3600 MOVEMENT The result of over 50 years in mastering the automatic high-frequency chronograph movement. The latest version of the El Primero calibre, dubbed the El Primero 3600, operates at the high frequency of 5Hz, with the ability to offer a true 1/10th of second indication. Its autonomy has also been efficiently extended to a power reserve of 60 hours.