|Diameter:||43.0 mm (19 ligne)|
|Complications:||6-Column Chronograph, Chronograph, Column Wheel Chronograph, Monopusher Chronograph|
|Production: 1910 –|
Valjoux Cal. 1 was a pocket watch column wheel chronograph movement. Introduced in 1910, it was produced through at least the 1920s. A monopusher movement, it featured an unusual six-column wheel with asymmetrical columns to control the chronograph function.Images are taken from official publications and are used here for commentary and educational purposes. Copyright is held by the original owner as noted.