|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.