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