The zpotential free switching with spring-returnz receives and switches devices such as the bell. This product's special feature is that only the zspring-returnz is used during assignment in Basic mode. Here, the output is switched as long as the assigned pushbutton/sensor is being actuated (function of a doorbell button). Even when resetting to factory settings (reset) reassigning a pushbutton/sensor in basic, only the spring-return is available. All known and best-established functions remain unchanged in Comfort mode. Power is supplied via the electrical power networks. Other voltages than the mains voltage may be switched . The device is built into the switch, branch, or installation box directly in the lamp shroud.