By adding an extender cord to the output connector of your ModCon you can

1) Protect the ModCon output connector from wear, thereby increasing the number of tests you can perform before you need to re-work the connector

2) Change connector type on the ModCon output. That means you can test systems with different input connectors just by switching the extender cord. For example you could test systems terminated with both SC and LC connectors with same ModCon just by switching the extender cord.