You will need a BT NTE5 if you do not have one, whatever goes to 2 & 5 from BT at present will go to A & B on the NTE5. You only need the bell wire on EXTENSIONS(the is no bell wire from the BT network), that is, any cabling at the current master that goes to another socket. The ADSL faceplate replaces the lower front of the NTE5. Please email us if you have any queries-support@run-it-direct.co.uk