NRR23dB noise reduction rating. HD speakers. Omni directional microphones. Low noise/frequency tuned for natural sound clarity. Full dynamic range HD speakers for clear, balanced sound. Sound activated compression--0.02 second reaction time. Sound dampening composite housing. Audio input jack. Kryptek pattern. Ultra compact and collapsible. Slim profile rubberized cups. Requires (2) AAA batteries (included). Color: Black. Clam packed.