The E-Max amplifies sounds below 85 decibels, which amplifies normal communication, range commands, and environmental sounds. Above 85 decibels, the microphones shut off for a split second to protect the shooter’s hearing. Two microphones – one in each cup – give the user true stereo sound and allow the user to identify the directional source of a sound. Includes an integrated audio input jack allowing music to be played. Runs on 2 AAA batteries (not included). 23db Noise Reduction Rating.