Prefer to go portable? Put this in your flight bag. Our IISX is a 2-place, voice activated mono intercom with modular design. Powerful. Functional. Expandable to 4-place. And it can run off your aircraft battery through the included cigarette lighter adapter or use a 9 volt battery if you have no electrical system. It's an intercom you can carry anywhere into the wild blue yonder. Just plug in and take off.