Sometimes you want to talk to two people separately but that was rather difficult if you had one head set plugged into the walkie talkie. The PTT allows you to switch communication between two people so you can talk to them separately. This will prove incredibly useful if you're team leader and you want to give your team mates different commands without confusing them.
There is a headset connector at the top and two separate connecters underneath that connect to two different walkie talkies. You can raise and lower the volume depending on the environment you're in. You can choose a non battery mode and continue using it without wasting battery!