Radians R-3700 Bluetooth Quad Mic is an electronic sound amplification earmuff featuring Bluetooth wireless technology. Four independent microphones provide a full surround sound experience that amplifies low sound level noises while compressing sounds that exceed safe levels. Compact folding feature for easy storage. Works wirelessly with most smart devices. Features: Electronic compression to protect hearing Amplifies environmental sounds for enhanced hearing 4 microphones Bluetooth connectivity compatible with most smart devices LED on/off indicator light Adjustable headband folds for compact storage 3.5 mm stereo input jack and patch cable (included) enable playback from smartphone or digital audio player