2 directional microphones Full dynamic range, high-fidelity speakers for clear balanced sound Low noise / frequency tuned for natural sound clarity Single volume control Sound dampening composite housing Sound activated compression - 0.02 second reaction time Audio input jack Recessed volume control knobs Comfortable headband with metal wire frame External battery door Operates on 2 AAA batteries - included Smooth, clear hearing enhancement sound quality Autoblocker technology compresses loud sounds over 85 db 25 db snr- hearing protection Reduces wind noise Sweat & water resistant Compact design gives you comfort in a small sized ear muff Dual purpose technology lets you enhance sounds and protect your hearing at the same time 2 AAA batteries included