Noise Reduction Rating (NRR): 23dB; Two Omni Directional Microphones; Full Dynamic Range HD Speakers for clear balanced sound; Low Noise / Frequency tuned for natural sound clarity; Independent Volume Controls; Sound dampening composite housing; Sound Activated Compression - 0.02 second reaction time; Audio Input Jack; Recessed Volume Control Knobs; Comfortable headband w/metal wire frame; Operates on 2 AAA batteries (included)