This cable is for the intercom side of the Bluewave. It connects the Crystal Mic to the aircraft intercom
 
Options are
1. General Aviation intercom
2. Airbus (XLR5) intercom
3. Helicopter / Military (U174) Intercom
 
The GA intercom cable comes in 2 lengths: Standard is 20 in and Long is 43 in (tip to tip)