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 earmuff amplifies low level sounds while compressing noises that exceed safe levels Bluetooth connectivity compatible with most smart devices Four microphones provide surround sound LED ON/OFF indicator light prevents unintentional battery discharge Premium adjustable headband Compact folding feature Specifications: Color: Pewter/Black Battery Type: AAA NRR Rating: 24 Decibels Sound Amplification: Yes Auto Shutoff: No