This special breakout box enables you to access all pins on a 16 pin OBD2 connector via 4mm female banana sockets for most makes of cars using OBDII Diagnostic Link connector.
Some cars use a lot of different K-lines for it's different systems like engine ECU, ABS, etc. this is needed for most scantools if you want to access all the systems just by plugging the K-line into the right socket of the system (examples of such cars are Fiat, Opel, Mercedes Benz, etc)