Replacement foam microphone windscreen for Bose A20 and X. Replacing your old windscreen will increase the noise-canceling performance of your Bose X or Bose A20 Aviation Headset. This mic muff reduces ambient noise and helps keep wind pressure from activating the microphone. The windscreen is easily replaceable and slides quickly over the headset microphone and is secured with included rubber o-ring. Hobbs Flyer replacement for OEM part# 16003.