The Tissot 2391 is a mechanical watch movement featuring a pin-lever escapement. In later samples, the hairspring terminal is glued. The movement includes a stem mechanism without a setting-lever spring. A unique aspect of this movement is that the train and hand gear are separately driven by the barrel. The movement includes automatic winding, a sweep second function, and a digital display that shows the minute and jumping hour. The Tissot 2391 was commonly used in watches around 1975.