An electroacoustic transducer has a membrane, which has a membrane axis and a ring-shaped pleats area, the pleats area being provided with a multitude of pleats, in which diametrically opposed pleats are embodied differently with regard to at least one of the pleat parameters. The method an apparatus provides for the formation of a preform of casting material and the placement of the material in a cavity mold which is precisely temperature controlled, has vacuum assist operating throughout the molding operation. A locking body configured to be locked with the mounting member is held on the mounting plate via the holding member. Through this invention, resource supplies and consumptions and thus charges and revenues can be tracked and accounted for simultaneously. A redesigned hanger, a large ball pivot, a load-redirecting pivot cup, a tapered kingpin and other improvements give the hanger a high kingpin ratio and a high angle of mechanical advantage, thereby improving the performance and turning characteristics of the truck.