Interfaces the David Clark H3530 / H3531 ground support headset to the aircraft. Contains a momentary Push-to-Talk (PTT) Switch to key the headset's microphone. This is critical for preventing background noise from interfering with pilot communications between the tower and crew prior to and during pushback. Belt clip allows for easy attachment to belt or clothing. Quality components and construction provide added durability for dependable performance in extreme conditions. Cords are shielded against RF interference and are chemical-resistant for superior durability.