Used a Bose X for 2 years now on jet, turboprop and some piston singles. Though I first thought it was overkill on the Boeing, I would not go without it now. Adaptersto XLR5 single plug: Bought one from my local pilot shop, I think it was built by Pilot Avionics), lost it and got another one that actually came from Sennheiser. They have them for their HMEC 45's, but they work fine with the Bose.