This is a Caldwell Earmuff, model 487-557.
The Low-Profile E-Max hearing protection combines great circuitry with a low-profile ear cup that's ideal for shotgun shooters and action shooters. The E-Max(R) 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).
Features:
Amplifies Sounds Below 85 Decibels
Microphones Shut Off Above 85 Decibels
Noise Reduction Rating 23 dB