Abstract: A device for selectively interconnecting a plurality of telephone key sets with a number of incoming telephone lines is disclosed. The device facilitates rapid and easy cross connecting of telephone key sets on specific premises with selected incoming lines without the requirement for the work to be accomplished by skilled technicians. The subject device includes a terminal station which is interconnected between incoming lines and a plurality of individual key sets located within a particular prescribed area. The interconnection of the individual sets with incoming lines is accomplished by cross connecting connectors for the individual key sets and connectors for the lines with jumper cables. The jumper cables have four or more conductors with an extra conductor being used when it is desired to have the designated key set ring.