This adapter allows you to connect an RJ11 networking cable to a standard BT phone socket. The RJ11 connector is commonly found on fax machines, analogue dial-up modems, and US-made telephones. The signals carried by the cables are identical to that of a standard telephone, only the connector shape differs. Simply connect your RJ11 cable into the back of the adapter, and then plug the adapter into your phone socket. It requires no configuration or power supply to operate and is ROHS Compliant.