If your set top box or recorder is a Freeview receiver, you will require a roof top aerial. You will need to connect the aerial wall socket with an RF cable to the socket labelled RF IN on the back.
If your set top box or recorder is a Freesat receiver, you will require a satellite dish aligned with Astra 28.2°E and Eutelsat 28A. You will need to connect the satellite dish via an LNB cable to the LNB socket on the back of the unit.
You can replace a Freeview box with a Freesat box only if you have a satellite dish.