With the surface-mounted transmitter RTS43, the switching functions of existing switches or buttons can be expanded with a radio interface. Up to two buttons or switches can be connected. The transmitter checks whether voltage has been switched through to a switch or button and sends the corresponding Easywave code A or B to an Easywave radio receiver, which then switches a connected consumer. The RTS43 is characterized by its high transmission power. It therefore achieves ranges of up to 300 m in the open field.