The SR112 Electronic Earmuffs are Stereo Earmuffs and work just great. The speakers shut down in milliseconds when the noise goes over 85dB. They also amplify the sounds below 20dB, which is excellent for hunters in woods. Moreover the micrhophones allow you to hear directionally the sounds up to 100 yards away! The volume is controlled independently on each earpiece. The adjustable over-head band is made of stainless steel for a great comfort and a better protection of the hear. The cushions are filled with super-soft liquid-foam and at the end of the day you won't even realize you used the SR112 Earmuffs! The SR112 Earmuffs and all of them are foldable for better storage and carrying. The NRR is 20dB