It is an additional wire for above phones to connect with UFS, Twister Flasher, Tornado Box (UFS2, UFS3), HWKuFs and all other boxes with compatible RJ45 socket.
This cable fits the following models: Samsung E108, E330, E330N, E335, E338, E630, E635, E638, E700, E708, E800, E800N, E808, E820, S500, S508, X100, X108, X460, X468, X490, X495, X497, X600, X608, X620, X628, X640, X648, X650, X656, X658