A rattrapante, also called a split seconds chronograph, is a complicated chronograph timepiece with two independent second hands that can be stopped and started independently. This function allows the wearer to measure, for example, multiple events at once or measure a split time to an exceptionally high degree of precision. The second hand can be "caught" or stopped without affecting the hand of the main chronograph, so intervals can be measured that are closely spaced or run consecutively.

This rattrapante mechanism presents a perfect example of high art in watchmaking: it involves very fine mechanical engineering, where both second hands should be able to work independently but not interfere with one another. Quite appropriate for a top collector piece because of its functionality, this complication speaks for many of technical mastery.