They are hard-wired in for fixed installations, and are exactly the same size as a standard double 13amp socket.
This means that you can activate any equipment without any cable connection, up to 20 metres away. Because it is radio controlled, you do not have to point it or keep it in a visual line with the controller.
You can use any number of control points with any number of transmitters at once and they will not get confused.
You can also use the Radio remote units manually.