These parts are located on the plate on the dial side. They are used to switch between the winding and time setting functions by means of a trigger, a lever (an arm sliding in the groove of the sliding pinion), and springs and jumpers.

The quality of workmanship of these pieces may or may not contribute to the granting of seals of quality such as the Geneva hallmark, where wire springs, for example, are not allowed.

Also, in the highest quality the springs have a clearance of about five to ten hundredths of a millimetre at the level of the blade on the side of the plate in order to prevent them from scratching the latter when they do their work.