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. It has a compact folding feature for easy storage and an adjustable headband. The R-3700 also features a LED on/off indicator light prevents unintentional battery discharge and works wirelessly with most smart devices. This model has a black/gray finish and a 24 dB NRR.