The new E-Max Behind-the-Head hearing protection combines great circuitry with a low profile ear cup thats ideal for shotgun shooters and action shooters. The E-Max amplify sounds up to 20dB, controlled by the volume dial on the right ear cup. This is beneficial for normal communication, range commands, and environmental sounds. With sounds above 85 decibels, the speakers shut off for a split second to protect the shooter?s hearing. Two microphones, one in each cup, give the user true stereo function and help the user to localize sound. Product Specifications 21NRR rating Adjustable volume control Audio input jack Stereo sound Cushioned foam ear cups Power indicator light