FAA TSO approved. Pilot fail safe feature allows pilot to always hear radios. Works with all brands of General Aviation headsets. Reversible face plate included for vertical or horizontal mounting. Radio priority assures that ATC hears only the crew member transmitting. Installation hardware included, including jack kit and pre-wired harness. WARRANTY: Five years parts and labor. The Intercom That Set The Standard Sigtronics pioneered the voice activated intercom market in 1974 and continues to deliver value and performance today in the 4 or 6 place FAA TSO approved SPA-400 / SPA-600 intercom series. With fail safe features that allow pilots to always hear the radio even if the intercom is off, and radio priority that assures ATC only hears the crew member transmitting, the SPA intercom series is the standard by which all others are judged. Individual Mic Bias Allows The Use of Different Brands of Headsets General aviation headset microphones draw power from the intercom or radio mic line. Some poorly designed intercom systems hook all the headsets to one mic line so that all the headsets must share the same power. Because different headsets have different power requirements, one headset may draw just enough power to work but there may not be enough power left over for any of the other headsets to function. With this type of design two identical headsets will work most of the time but get different types and models then you will have a problem. The only way to fix this is to modify or replace the intercom system with one that uses separate mic input lines. All Sigtronics intercom systems use separate mic input lines and do not have this problem. Compact Size Choose either rectangular (horizontal or vertical) or circular faceplate mounting configuration to fit anywhere in the cockpit. With a compact 2.5" x 1" sized panel, the SPA system will easily fit in the tightest panels. All installation hardware including jack kit and pre-wired harness are included
