Peltor Tactical 6S Behind Head Earmuff: * NRR 19 dB * Folding design for easy storage * Behind-the-head neckband designed for cap and hat wearers * Electronics limit amplified sounds to 82 dBA within 5 milliseconds * Active-volume provides distortion-free amplification of low level sounds up to 19 dBA * Stereo microphones provide enhanced sound detection * Independent volume controls on each cup * 300+ hours of operation on batteries * Requires 4 "AAA" batteries (not included)