The Vs.Kfz.31 Leichttraktor (Light tractor), also known at the time as the Kleintraktor (Small tractor), was a prototype German light tank, of which four distinct versions were made. It was developed and tested in secret at the Soviet-German Kama facility, during the Weimar Republic. This was part of the Leichttraktor, also known as the Kleintraktor, project. The tank was designed *around* 1929 and used through early WW2 as a training vehicle. In spite of having a 37 mm cannon, it was rejected in favor of the Panzer I, in a competition to make a new light tank for Germany, like the Grosstraktor project at the same time.