The RJ14-S  is an eighteen foot cable assembly used to separate two line RJ-14 phone jacks (L1+L2) into individual RJ-11 jacks or plugs. It can also be used to combine two phone lines from two RJ-11 jacks or cables onto a single RJ-14 plug.
      It has an eighteen foot four conductor ivory cable with a 6P4C (six position four conductor) modular phone plug on one end. The other end of this cable is terminated in a small ivory box with two TJ-11 jacks. One jack is (labeled L1) has its center two contacts connected to the center two wires in the 18' cable. The other jack (labeled L2) has its center two contacts connected to the outer two wires in the 18' cable.
      The RJ14-S also comes with two ten inch phone cables with a 6P4C modular phone plug on both ends. These cables are used to convert the female jacks into male plugs.