Chronographs
Chronographs are watches with a stopwatch function. Most have two or three sub-dials for measuring minutes and hours. When used in conjunction with specialized scales on the watch dial, it can perform many different functions, such as determining speed or distance (tachometer and telemeter). Some chronographs can time more than one event simultaneously, which is called split seconds chronograph, or rattrapante in French and Doppelchrono in German.