2-Line adapter 4-conductor converts any single two-line modular phone jack into three separate lines: 1 outlet for line 1 1 outlet for line 2 2nd and 3rd outlet carries lines 1 and 2 plugs directly into phone wall plate. Plugs Directly Into Phone Wall plate Converts Any Single Two-Line Modular Phone Jack Into Three Separate Lines 1 Outlet for Line 1