Watch Terminology Dictionary

A chronograph that uses a single button to start, stop, and reset. While this simplifies the design, it has the disadvantage that the chronograph cannot be restarted unless it is stopped. It is often seen in classic chronographs, and is still sometimes used today in chronographs with small movement space. In 1923, Breitling developed a movement that started with a push button and stopped and reset to zero with the crown. In 34, this was changed to a push button at the 2 o'clock position for start/stop and a push button at the 4 o'clock position for reset. From then on, the one-push chronograph disappeared.