This is what my invoice lists:
#90015 / MicMuff - Electret Type Mic ------Price $13.00
There number is:
I know the muff is specific to the boom on the headset I listed. If you tell them what you have they will give you the #
I agree, My system is dead silent with no shut down noises. Plus the music dims down lightly without a cut off type sound. I have yet to have a problem with it.