I bought one of these :
It’s really 4 remote controlled relays able to switch 16 Amps mains if installed correctly.
The remote control is a FS20 4 channel switch. In other words with my current setup (FHEM home automation software) I can control these 4 relay individually, foe example to turn on and off the hot water and central heating valves in the house heating system.
And now that I can get replacement 24V motors for the valves (they are normally mains voltage motors) it’s even remotely (!) legal to do this.
You can see these in FHEM as :
and even better – I can now control FHEM from my Ruby house monitoring scripts (more about this later)