TRACKR Blu Earmuffs offer advanced sound enhancement, hearing protection and 5.0 Bluetooth audio. Turn your sound enhancement up or down to your exact desired level, then enjoy clear hearing for any environment you want. then notice while you are hearing everything you want, the axil technology will automatically compress damaging loud sounds to give you the hearing protection you need- all at the same time, without interrupting your clear hearing. Features Autoblocker technology compresses loud sounds over 82 dB;27 dB SNR hearing protection; reduces wind noise; sweat and water resistant; sound activated compression, 0.02 second reaction time; single volume control;external battery door; audio input jack and a comfortable headband with a metal wire frame. Includes two AAA batteries.