This adaptor is used for communication over your PC network via your actual Pilots headset. Simply plug the two jacks into the audio -in sockets on the back of your PC and plug your headset jacks into the two sockets on the adaptor.
The missing info is that this needs a 9v battery to function. Also if you leave your headset connected for long periods there is probably a small drain on the battery, it would be better with an on/off switch and an indicator LED. Other than that it works fine with my PC and Dave Clarks headset.