The Caldwell E-Max hearing protection combines great circuitry with a standard ear cup for better protection. The two microphones in the E-Max amplify sounds below 85 decibels, which amplifies normal communication, range commands, and environmental sounds. Above 85 decibels, the microphones shut off to protect the shooters hearing. Ear cup width is 1.75 inches and two AAA batteries are required but not included. Enabled with one stereo microphone in each cup, the user can localize sound from all directions.Features : Amplifies Sounds Below 85 Decibels Microphones Shut Off Above 85 Decibels Stereo Microphone in Each Cup