A non-isolated coax socket is a standard socket. If you wish to install a socket to connect your TV coax lead into, this is what is required. Also, this version must
be used for satellite installation as a two way signal is required. The satellite box does not only receive a signal, it also sends a signal back to the satellite dish. An isolated coax socket will block the return signal.
An isolated socket lets the signal through from the aerial/satellite dish but does not allow any kind of return signal/current. This type of socket would be used where a communal dish or aerial is installed, such as in an apartment block. The isolated socket blocks interference from receivers (televisions, digital boxes, satellite boxes) which spoils the signal which the rest of the users receive.