A microfilter is a device that allows broadband to work at the same time as your phone service. Without microfilters you may get problems with your broadband or hear noise on your phone line.
Master socket with one socket
If your master socket has one socket, you must use a microfilter for every phone socket in your home with any phone or broadband equipment plugged in (including your Hub, phones, answer machines, digital TV boxes and alarm systems).
Master socket with two sockets
If you've got a double socket like one of those below, you must always plug your Hub into the broadband connection on your master socket. If you plug it into a phone socket or extension, it just won't work.
You don't need microfilters - not for your Hub or any other devices connected to phone sockets or extensions.