The Caldwell E-Max electronic stereo ear muffs limit sounds above 85 dB by automatically shutting down the speakers when there is a loud noise situation. Enabled with one stereo microphone in each ear cup, the user is able to localize sound from all directions. The E-Max amplifies normal sound levels to enhance hearing when the earmuffs are being worn, yet will automatically shut down when noise levels exceed 85 dB. The comfortable, compact E-Max is a new low-profile design and operates on two AAA batteries (not included).