The function of the four changeover contacts is switchable for each individual relay, allowing for momentary or toggle operation, as well as switching operation for remotely controlling various consumers. The relays therefore either switch only for the duration of the button press or change their state between on and off with each new button signal. The receiver evaluates each radio signal from the corresponding transmitters of the SH-12 series, with up to 60 units being teachable. The assignment of the transmitter buttons is already firmly assigned to the four potential-free changeover contacts. Two selectable frequencies (433.62 MHz or 434.22 MHz) and various control LEDs are available. Combined with a special transmission technique, this results in extremely low interference operation, with ranges of up to 1000 m possible. There is also feedback for the transmitted signal to the (handheld) transmitter via LED. The ready-built 4-channel receiver comes in a surface-mounted housing with four relays for connection to 12 - 24V DC and a λ/4 wire antenna.