3M PELTOR ComTac VI Quick Manual page 4

PTT for face-to-face communication
Fig 8
Double press the PTT button to toggle
between the different modes, NIB PTT On -
NIB Off - NIB Vox On.
"NIB PTT On /
NIB Off /
NIB VOX On.
2.
Fig 9
Press and hold the PTT button to
transmitt.
2.