posted 11-07-2018 12:26 AM
Each side has both an ear cup and microphone that are wired into a common connector plug. This serves as redundancy should one ear piece or microphone fail.The snoopy cap design was not an Apollo specific idea, it can be found in many aviation arenas including hypobaric chambers, aerobatic flying and others.
The Apollo snoopy cap has a few differing designs, many have a section of chamois in the forehead band to absorb sweat, however Neil Armstrong's cap did not have this feature, this is why his cap fits differently over his forehead and why his cap has a dark stripe over the top.
The dark colour is black, made of a material that colour fades to brown. Originals have faded over time, and several replicas can be found manufactured from a brown material, perhaps emulating what can be found in museums. Ryan Nagata discusses this during an interview about some of the costumes manufactured for the movie "First Man." He has also made items for Adam Savage (Mythbusters) and there is a Tested.com video that covers this.
The Historic Space Systems website also has some excellent information regarding this subject and is highly recommended for any Apollo or Gemini fan. They do some amazing work.