Twin Pack: The Wireless Phone Jack is a fantastic product which offers you 50 metres of wireless phone line, meaning you can have an extra socket in your home without the need to install wires and other equipment, which can be both expensive and time consuming. Telephone sockets are often in high demand in the home, with current technology such as telephones, fax machines and PC modems. The Wireless Phone Jack is the perfect solution for when you need an extra connection. This well-designed plug is easily inserted directly into any power socket within your home, without the need for any annoying wires! Just Plug in a Wireless Phone Jack and Communicate - it's that simple! Extension Unit: RTX Wireless Phone Jack Slave Unit. Up to 4 Wireless phone Jack Slaves (Receivers) can be paired with RTX Wireless phone Jack Master (Transmitter Unit) to create additional wireless telephone extensions.