The P.9100 calibre is the first automatic movement with chronograph functions developed by Officine Panerai and it is produced entirely in the Panerai manufacture in Neuchâtel, with materials and standards of workmanship at the peak of the sector in terms of technology, quality and reliability. With a chronograph with a vertical clutch and column wheel, the new calibre is unusual in that the chronograph minutes are displayed by a central hand which jumps forward once every 60 seconds. It also has the useful flyback function. This enables the chronograph hands which are already running to be returned instantaneously to zero and restarted without first having to stop them, return them to zero and then restart them. This function is controlled by the push-button at eight o’clock, which is also used to return both hands to zero when the chronograph has already stopped. The two spring barrels in series give a power reserve of 72 hours. The choice of the double spring barrel enables thinner, longer springs to be used, which is beneficial for the duration and evenness of the supply of energy.