This is an adapter with an RJ11/RJ12 or RJ45 connector at one end and a DB25, unpinned, connector at the other end. All wires are terminated with the correct gender pin and only need to be gently inserted into the DSUB connector.
Pinout for RJ45
Pin 1 Blue
Pin 2 Orange
Pin 3 Black
Pin 4 Red
Pin 5 Green
Pin 6 Yellow
Pin 7 Brown
Pin 8 White