The springs in the contact sockets, the surface of which is gold-plated or electro-tin-plated as standard, are used to compensate for the tolerances of connecting pins. They can be used for connecting pins with a diameter between 0.36 mm and 2.36 mm, the usual plug-in diameters are 1 mm, 1.5 mm and 2 mm, but there is the option of having special solutions made according to customer drawings.