With this 5 pin splitter, you can make your 4 person intercom system connect to 5 people in the same vehicle. Simple connect this splitter at your intercom and add a 5th cable to the back seat.
With this 5 pin splitter, you can add an additional headset position to your intercom setup. Turn a 2 person intercom into a 3 person intercom or a 4 person intercom setup into a 5 person setup. Simply connect this splitter at your intercom and add an additional cable to the back seat.