Bose A20 LEMO to Helicopter Jack Adaptor

If you fly helicopters you’ll most likely be looking for a headset with a single plug. It’s slightly shorter and fatter than either of the fixed wing plugs. This single plug (7.1 mm / 0.281 inch diameter) provides both microphone and audio to the ear cups. It’s generally known as a U-174/U plug or the U-93A/U plug (Nexus TP120).

If you own an aircraft, or you fly something like a Cirrus or a newer Beechcraft, you might find a 6-pin circular type jack in your panel. This panel power plug is called a LEMO or Redel connector and is also referred to as a “Bose Style connector”. This will allow you to plug any Redel equipped ANR (Active Noise Reduction) headset directly into the panel. This single 6-pin jack will provide audio, microphone, as well as power for the ANR in the headset so you can skip the batteries.