3m says these are discontinued and not supported - 3M Peltor Sound-Trap Slim Line Electronic Earmuff Tactical Headset Headband

The microphone and sound-enhancing part of the earmuffs don't work, even with 4 new batteries installed, so I called 3M for support and the sales rep says the model # and serial # indicate these earmuffs were discontinued in 2018 (or earlier), and said he had no idea why Optics Planet is selling discontinued products. #Fail